Journal articles: 'EIS-biosensor'

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Oliveira, A. C., and L. H. Mascaro. "Evaluation of Acetylcholinesterase Biosensor Based on Carbon Nanotube Paste in the Determination of Chlorphenvinphos." International Journal of Analytical Chemistry 2011 (2011): 1–6. http://dx.doi.org/10.1155/2011/974216.

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An amperometric biosensor for chlorphenvinphos (organophosphorus pesticide) based on carbon nanotube paste and acetylcholinesterase enzyme (CNTs-AChE biosensor) is described herein. This CNTs-AChE biosensor was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The SEM result shows the presence of CNTs and small lumps, due to the enzyme AChE, which has a type of cauliflower formation. From EIS analysis is possible to observe increasedRtcfor CNTs-AChE biosensor when compared to the carbon nanotube paste electrode for the reaction [Fe(CN)6]4−/3−. Using a chronoamperometric procedure, a linear analytical curve was observed in the4.90×10-7–7.46×10-6 M range with limit of detection of1.15×10−7 M. The determination of chlorphenvinphos in the insecticide sample proved to be in agreement with the standard spectrophotometric method, with a 95% confidence level and with a relative error lower than 3%. In this way, the CNTs-AChE biosensor presented easy preparation, fast response, sensitivity, durability, good repeatability, and reproducibility.

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Manickam, Arun, Aaron Chevalier, Mark McDermott, Andrew D. Ellington, and Arjang Hassibi. "A CMOS Electrochemical Impedance Spectroscopy (EIS) Biosensor Array." IEEE Transactions on Biomedical Circuits and Systems 4, no. 6 (December 2010): 379–90. http://dx.doi.org/10.1109/tbcas.2010.2081669.

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Le, Hien T. Ngoc, and Sungbo Cho. "Sensitive Electrochemical Detection of Phosphorylated-Tau Threonine 231 in Human Serum Using Interdigitated Wave-Shaped Electrode." Biomedicines 10, no. 1 (December 22, 2021): 10. http://dx.doi.org/10.3390/biomedicines10010010.

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The development of an electrochemical biosensor for the detection of phosphorylated-tau threonine 231 (p-tau231), a biomarker of Alzheimer’s disease (AD), has yet to be achieved. Therefore, in this study, we developed a simple, small size, cheap, and sensitive electrochemical biosensor based on an interdigitated wave-shaped electrode via an activated self-assembled monolayer to preserve a specific anti–p-tau231 antibody (IWE/SAM/EDC-NHS/anti–p-tau231). Detection of p-tau231 in human serum (HS) using the biosensor was undertaken using electrochemical impedance spectroscopy (EIS). The change in charge-transfer resistance (Rct) in the EIS analysis of the biosensor indicated the detection of p-tau231 in HS within a wide linear range of detection (10−4–101 ng mL−1), and a low limit of detection (140 pg mL−1). This lower limit is less than the detection level of p-tau231 in cerebrospinal fluid (CSF) (700 pg mL−1) of AD patients and the level of CSF p-tau231 of patients with mild cognitive impairment (501 pg mL−1), demonstrating the possibility of using the biosensor in detection of p-tau231 at early stage AD. A high binding affinity and low dissociation constant (Kd) between anti–p-tau231 and p-tau231 in HS was demonstrated by using a biosensor and Kd was 7.6 pM, demonstrating the high specific detection of p-tau231 by the biosensor. The good selectivity of the biosensor for the detection of p-tau231 with differential analytes was also examined in this study.

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Gasparyan, L. F., I. A. Mazo, V. V. Simonyan, and F. V. Gasparyan. "EIS Biosensor for Detection of Low Concentration DNA Molecules." Journal of Contemporary Physics (Armenian Academy of Sciences) 55, no. 1 (January 2020): 101–9. http://dx.doi.org/10.3103/s1068337220010144.

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Zhou, Yaoyu, Lin Tang, Xia Xie, Guangming Zeng, Jiajia Wang, Yaocheng Deng, Guide Yang, Chen Zhang, Yi Zhang, and Jun Chen. "Sensitive impedimetric biosensor based on duplex-like DNA scaffolds and ordered mesoporous carbon nitride for silver(i) ion detection." Analyst 139, no. 24 (2014): 6529–35. http://dx.doi.org/10.1039/c4an01607f.

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Jamshaid, Talha, Ernandes Taveira Tenório-Neto, Abdoullatif Baraket, Noureddine Lebaz, Abdelhamid Elaissari, Ana Sanchís, J. Pablo Salvador, et al. "Development of Novel Magneto-Biosensor for Sulfapyridine Detection." Biosensors 10, no. 4 (April 21, 2020): 43. http://dx.doi.org/10.3390/bios10040043.

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In this work, we report the development of a highly sensitive biosensor for sulfapyridine detection based on an integrated bio micro-electromechanical system (Bio-MEMS) containing four gold working electrodes (WEs), a platinum counter electrode (CE), and a reference electrode (RE). Firstly, the cleaned WEs were modified with 4-aminophenylacetic acid (CMA). Then, (5-[4-(amino)phenylsulfonamide]-5-oxopentanoic acid (SA2BSA) was immobilized onto the transducers surface by carbodiimide chemistry. The analyte was quantified by competitive detection with SA2BSA immobilized on the WE toward a mixture of Ab155 antibody (with fixed concentration) and sulfapyridine. In order to obtain a highly sensitive biosensor, Ab155 was immobilized onto magnetic latex nanoparticles surface to create a 3D architecture (Ab-MLNp). Using electrochemical impedance spectroscopy (EIS), we investigated the influence of the Ab-MLNp on the sensitivity of our approach. The optimized system was analyzed, as competitive assay, with different concentrations of sulfapyridine (40 µM, 4 µM, and 2 nM) and with phosphate buffer solution. From data fitting calculations and graphs, it was observed that the EIS showed more linearity when Ab-MLNp was used. This result indicates that the magnetic latex nanoparticles increased the sensitivity of the biosensor.

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Li, Jing, Byung Kun Kim, Kang-Kyun Wang, Ji-Eun Im, Han Nim Choi, Dong-Hwan Kim, Seong In Cho, Won-Yong Lee, and Yong-Rok Kim. "Sensing Estrogen with Electrochemical Impedance Spectroscopy." Journal of Analytical Methods in Chemistry 2016 (2016): 1–6. http://dx.doi.org/10.1155/2016/9081375.

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This study demonstrates the application feasibility of electrochemical impedance spectroscopy (EIS) in measuring estrogen (17β-estradiol) in gas phase. The present biosensor gives a linear response (R2=0.999) for 17β-estradiol vapor concentration from 3.7 ng/L to 3.7 × 10−4 ng/L with a limit of detection (3.7 × 10−4 ng/L). The results show that the fabricated biosensor demonstrates better detection limit of 17β-estradiol in gas phase than the previous report with GC-MS method. This estrogen biosensor has many potential applications for on-site detection of a variety of endocrine disrupting compounds (EDCs) in the gas phase.

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Antunes, Rafael Souza, Douglas Vieira Thomaz, Luane Ferreira Garcia, Eric de Souza Gil, Vernon Sydwill Sommerset, and Flavio Marques Lopes. "Determination of Methyldopa and Paracetamol in Pharmaceutical Samples by a Low Cost Genipa americana L. Polyphenol Oxidase Based Biosensor." Advanced Pharmaceutical Bulletin 9, no. 3 (August 1, 2019): 416–22. http://dx.doi.org/10.15171/apb.2019.049.

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Purpose: Jenipapo fruit (Genipa americana L) is a natural source of polyphenol oxidases (PPOs) whose potential in pharmaceutical analysis is noteworthy. Henceforth, this work reports the electrochemical study of a low-cost PPO-based biosensor produced from the crude extract of Jenipapo fruits and accounts a practical approach to employ this biosensor in the determination of methyldopa and paracetamol in pharmaceutical samples. Methods: In order to investigate the electrochemical properties of the biosensor, theoretical and practical approaches were employed, and both samples and the biosensor were analyzed through electrochemical impedance spectroscopy (EIS) and voltammetric techniques, namely: differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Results: showcased that the biosensor presented good analytical features, as well as low detection limits (8 μmol L-1 for methyldopa and 5 μmol L-1 for paracetamol). The relative standard deviation was less than 5% mid-assay. Conclusion: The use of this biosensor is a reliable, low cost and useful alternative in the pharmaceutic determination of phenolic drugs (e.g. methyldopa and paracetamol).

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Yang, Jie, Dawei Li, Zengyuan Pang, and Qufu Wei. "Laccase Biosensor Based on Ag-Doped TiO2 Nanoparticles on CuCNFs for the Determination of Hydroquinone." Nano 11, no. 12 (December 2016): 1650132. http://dx.doi.org/10.1142/s1793292016501320.

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A novel nanomaterial composed of copper and carbon nanofibers (CuCNFs) decorated with Ag-doped TiO2 (Ag–TiO[Formula: see text] nanoparticles was prepared through electrospinning, carbonization and solvothermal treatment. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The obtained composites were mixed with laccase and Nafion to construct novel hydroquinone biosensor. The electrochemical behavior of the novel biosensor was studied using cyclic voltammetry (CV) and chronoamperometry. The results demonstrated that the biosensor possessed a wide detection linear range (1.20–176.50[Formula: see text][Formula: see text]M), a good selectivity, repeatability, reproducibility and storage stability. This work provides a new material to design more efficient laccase (Lac) based biosensor for hydroquinone detection.

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Zhou, Yong. "Novel Approach to Fabricate an Amperometric Biosensor for Glucose Based on Nafion, Azure І and Gold Nanoparticles." Advanced Materials Research 345 (September 2011): 331–33. http://dx.doi.org/10.4028/www.scientific.net/amr.345.331.

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A novel approach to fabricate an amperometric biosensor for the detection of glucose was described. By means of self-assembled technique and the opposite-charged adsorption, Nafion(Naf), Azure І (Azu), gold nanoparticles (nano-Au) and glucose oxidase (GOD) were immobilized on the gold electrode subsequently. The GOD immobilized on the nano-Au monolayer was stable and retained its functional activity. The stepwise self-assemble procedure of the immunosensor was further characterized by means of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The factors influencing the performance of the resulting biosensor were studied in detail. The biosensor could detect the glucose in a range of 5.1×10-6~4.0×10-3mol/L.

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Nycz, Marta, Katarzyna Arkusz, and Dorota G. Pijanowska. "Fabrication of Electrochemical Biosensor Based on Titanium Dioxide Nanotubes and Silver Nanoparticles for Heat Shock Protein 70 Detection." Materials 14, no. 13 (July 5, 2021): 3767. http://dx.doi.org/10.3390/ma14133767.

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This paper presents the fabrication methodology of an electrochemical biosensor for the detection of heat shock protein 70 (HSP70) as a potential tumor marker with high diagnostic sensitivity. The sensor substrate was a composite based on titanium dioxide nanotubes (TNTs) and silver nanoparticles (AgNPs) produced directly on TNTs by electrodeposition, to which anti-HSP70 antibodies were attached by covalent functionalization. This manuscript contains a detailed description of the production, modification, and the complete characteristics of the material used as a biosensor platform. As-formed TNTs, annealed TNTs, and the final sensor platform—AgNPs/TNTs, were tested using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction analysis (XRD). In addition, open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) of these substrates were used to assess the influence of TNTs modification on their electrochemical characteristics. The EIS technique was used to monitor the functionalization steps of the AgNPs/TNTs electrode and the interaction between anti-HSP70 and HSP70. The produced composite was characterized by high purity, and electrical conductivity improved more than twice compared to unmodified TNTs. The linear detection range of HSP70 of the developed biosensor was in the concentration range from 0.1 to 100 ng/mL.

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Štukovnik, Zala, Regina Fuchs Godec, and Urban Bren. "The Use of Yeast Saccharomyces Cerevisiae as a Biorecognition element in the Development of a Model Impedimetric Biosensor for Caffeine Detection." Acta Chimica Slovenica 69, no. 2 (June 15, 2022): 378–84. http://dx.doi.org/10.17344/acsi.2021.7301.

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In the present study, an electrochemical-impedimetric biosensor using Saccharomyces cerevisiae as an effective biorecognition element was designed to detect caffeine. The presented biosensor consists of a previously developed stainless steel electrochemical cell constructed as a three-electrode system in the RCW side-by-side configuration. The electrochemical stability of the sensing electrode was evaluated by measuring the open circuit potential (OCP), and electrochemical impedance spectroscopy (EIS) was applied to determine the impedimetric response of the biosensor with Saccharomyces cerevisiae cells attached to the working electrode (WE) in the absence (0.9% NaCl) and presence (10 mg/mL in 0.9% NaCl) of caffeine. Moreover, the limit of detection (LOD) was determined. In this way, a new approach in biosensor development has been established, which involves assembling a low-cost and disposable electrochemical system to detect alkaloids such as caffeine. The developed biosensor represents a good candidate for detecting caffeine in beverages, foods, and drugs with the merits of time-saving, robustness, low cost, and low detection limit.

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Kesici, Ece, Ece Eksin, and Arzum Erdem. "An Impedimetric Biosensor Based on Ionic Liquid-Modified Graphite Electrodes Developed for microRNA-34a Detection." Sensors 18, no. 9 (August 31, 2018): 2868. http://dx.doi.org/10.3390/s18092868.

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In the present work, an impedimetric nucleic acid biosensor has been designed for the purpose of detection of microRNA (miRNA). Ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate (IL))-modified chemically activated pencil graphite electrodes (PGEs) were used for the sensitive and selective detection of miRNA-34a. After covalent activation of the PGE surface using covalent agents (CAs), the ionic liquid (IL) was immobilized onto the surface of the chemically activated PGE by passive adsorption. The electrochemical and microscopic characterization of the IL/CA/PGEs was performed by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and scanning electron microscopy (SEM). DNA probe concentration, miRNA target concentration, and also the hybridization time and wet adsorption time were optimized by using the EIS technique. Then, the hybridization occurred between specific DNA probes and miRNA-34a was immobilized onto the surface of the IL/CA/PGEs. The impedimetric detection of miRNA-DNA hybrid was performed by EIS. The detection limit (DL) was calculated in a linear concentration range of 2–10 µg/mL miRNA-34a target, and it was found to be 0.772 µg/mL (109 nM) in phosphate buffer solution (PBS) and 0.826 µg/mL (117 nM) in diluted fetal bovine serum (FBS). The selectivity of impedimetric biosensor for miRNA-34a was also tested against to other non-complementary miRNA sequences both in buffer media, or diluted FBS.

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Lai, Huat Choi, Suk Fun Chin, Suh Cem Pang, Magdline Sia Henry Sum, and David Perera. "Carbon Nanoparticles Based Electrochemical Biosensor Strip for Detection of Japanese Encephalitis Virus." Journal of Nanomaterials 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/3615707.

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We reported a disposable and sensitive electrochemical biosensor strip based on carbon nanoparticles modified screen-printed carbon electrode (SPCE) for rapid and sensitive detection of Japanese Encephalitis Virus (JEV). Amino group functionalized carbon nanoparticles were prepared from preformed chitosan nanoparticles. Japanese Encephalitis Virus (JEV) antibody was immobilized onto the surfaces of carbon nanoparticles through amide bonds formation between amino groups of carbon nanoparticles and carboxylic groups of JEV antibody. The analytical performance of SPCE electrochemical biosensor strip was characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). SPCE electrochemical biosensor strip exhibited a linear detection range of 1–20 ngmL−1 with a low detection limit of 0.36 ngmL−1 (at S/N = 3) for JEV, detection sensitivity was 0.024 ngmL−1 for JEV, and analysis results were obtainable within 10 minutes. The potential clinical application of this SPCE electrochemical biosensor strip was demonstrated by the detection of JEV in human serum.

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Cui, Han, Zhao Hao Wang, Qi Jin Wan, and Nian Jun Yang. "Self-Assembled Au Electrode for Direct Electrochemistry of Horseradish Peroxidase and Detection of Hydrogen Peroxide." Advanced Materials Research 704 (June 2013): 72–76. http://dx.doi.org/10.4028/www.scientific.net/amr.704.72.

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The H2O2 biosensor was prepared by continuous processes: 2,3-dimercaptosuccinic acid (DMSA) self-assembly monolayers gold nanoparticles (AuNPs) film by electrodepositioncovalent immobilization of horseradish peroxidase (HRP). In pH 7.2 phosphoric buffer solution (PBS), the HRP-AuNPs-DMSA-Au electrode exhibited a pair of well-defined cyclic voltammetric peaks in H2O2 solution, and the oxidation peak is about +0.4V versus saturated calomel electrode (SCE). The resulting substrates were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The biosensor exhibited remarkable sensitivity towards H2O2 and a wide dynamic range of 2-800 μM. The electrode retained 90% of its initial activity after 30 days of storage at 4°C.

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Zaid, Mohd Hazani Mat, Jaafar Abdullah, Nor Azah Yusof, Helmi Wasoh, Yusran Sulaiman, Mohd Fairulnizal Md Noh, and Rahizan Issa. "Reduced Graphene Oxide/TEMPO-Nanocellulose Nanohybrid-Based Electrochemical Biosensor for the Determination of Mycobacterium tuberculosis." Journal of Sensors 2020 (January 21, 2020): 1–11. http://dx.doi.org/10.1155/2020/4051474.

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A novel peptide nuclide acid (PNA) electrochemical biosensor based on reduced graphene oxide (NH2-rGO)/2,2,6,6-tetramethylpiperidin-1-yl)oxyl nanocrystalline cellulose (TEMPO-NCC) for the detection of Mycobacterium tuberculosis (M. Tuberculosis) is described. In this study, the nanohybrid films NH2-rGO/TEMPO-NCC were immobilized onto screen-printed carbon electrode (SPE) via a simple drop-coating method. The electrochemical characterization of the designed electrode was investigated using cyclic voltammetry (CV) and impedance spectroscopy (EIS). Meanwhile, the sensitivity and selectivity of the designed biosensor against M. tuberculosis were measured by the differential pulse voltammetry (DPV). The response of the PNA probe-modified (NH2-rGO)/TEMPO-NCC demonstrated that the fabricated biosensor was able to distinguish between complementary, noncomplementary, and one-base mismatch DNA sequences using methylene blue (MB) as the electrochemical indicator. The developed electrochemical biosensor exhibited a linear calibration curve in the concentration range of 1×10−8 M to 1×10−13 M with the limit of detection of 3.14×10−14 M. The developed electrochemical biosensor has also been tested with a polymerase chain reaction (PCR) product of M. tuberculosis DNA which has shown successful results in distinguishing between negative and positive samples of M. tuberculosis.

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Lee, So-Ra, Hyo-Eun Lee, Yun Ok Kang, Wan-Seok Hwang, and Seong-Ho Choi. "BienzymaticAcetylcholinesteraseandCholine OxidaseImmobilized Biosensor Based on a Phenyl Carboxylic Acid-Grafted Multiwalled Carbon Nanotube." Advances in Materials Science and Engineering 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/971942.

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Bienzymaticacetylcholinesterase(AChE) andcholine oxidase(ChOx) immobilized biosensor based on a phenyl carboxylic acid-grafted multiwalled carbon nanotube (MWNT) modified glass carbon electrode (GCE) and carbon-screen printed electrode (SPE) was fabricated for acetylcholine detection in human blood samples. Phenyl carboxylic acid-modified MWNT supports were prepared by electrochemical polymerization of 4-carboxyphenyl diazonium salts, which were synthesized by an amine group and sodium nitrite, on the surface of the MWNT-modified GCE and SPE in 0.1 M PBS. The successful fabrication of the AChE-ChOx-immobilized biosensor was confirmed via scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). The sensing range of the biosensor based on a GCE and SPE was 1.0~10 μM and 10~100 μM, respectively. The interfering effect of 0.1 M L-ascorbic acid, 0.1 M L-cysteine, and 0.1 M uric acid to 0.1 M acetylcholine was 3.00%, 9.00%, and 3.00%, respectively. Acetylcholine in a human blood sample was detected by the AChE-ChOx-immobilized biosensor.

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Wu, Hai Yun, Xiao Ying Guo, Ya Ping Yu, Yue Ming Zuo, Yong Wei, Yuan Liu, and Jin Xian Ma. "Rapid Quantitative Detection of E.coli O157:H7 by a Impedance Immunosensor Based on Four-Wire Interdigitated Microelectrodes." Applied Mechanics and Materials 738-739 (March 2015): 111–15. http://dx.doi.org/10.4028/www.scientific.net/amm.738-739.111.

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Rapid-response biosensing systems are necessary to counteract threats due to high-consequence pathogens. A disposable immunosensor suitable for quantitative determination of E.coli O157:H7 in pure cultures was investigated by electrochemical impedance spectroscopy (EIS). Electric responses of this biosensor for different cell concentrations at multi-frequencies were explored utilizing disposable screen-printed silver four-wire interdigitated microelectrodes (IMEs). Additionally, the best response frequency for the detection was studied, and the relationship between the impedance at this frequency and the concentrations of E.coli O157:H7 was established. The results showed that the impedance biosensor showed linearity from 1.15×103 CFU/mL to 1.15×106 CFU/mL at 100Hz, which yielded the model coefficient to 0.951.

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Štukovnik, Zala, Urban Bren, and Bren Rozman. "Model Electrochemical Biosensor for the Detection of Methanol in Aqueous Solutions with Yeast Cells." Acta Chimica Slovenica 68, no. 4 (December 15, 2021): 773–80. http://dx.doi.org/10.17344/acsi.2020.6545.

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An electrochemical device that serves as a model biosensor and contains yeast Saccharomyces cerevisiae as the active biological element was developed. Different configurations of the electrochemical cells were assembled and tested. Stainless steel was used in the electrochemical cell composition process and the surface of this metal electrode was modified with a thin layer of WO3 if necessary. The yeast Saccharomyces cerevisiae was adhered to the working electrode. The resulting model biosensor was then used to monitor the response to a 10% CH3OH. For detection of biological activity, the electrochemical impedance spectroscopy (EIS) method was applied with a portable potentiostat/galvanostat, where the Bode and the Nyquist plots were interpreted. The stability of the device was beforehand determined by measuring the open circuit potential (OCP). The topography of the electrodes was inspected using the techniques of scanning electron microscopy and optical microscopy. The investigated model biosensor as a case study for the development of more complex biosensors that utilize living cells as the active layer.

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Sedlackova, Richtera, Estrela, and Adam. "Effect of Graphene Oxide Modification on a DNA Biosensor Developed for the Detection of Methylated DNA Associated with Cancer." Proceedings 15, no. 1 (July 8, 2019): 13. http://dx.doi.org/10.3390/proceedings2019015013.

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Methylated DNA is a covalent post-translational modification, which plays a crucial role in pathological and physiological processes including several diseases, such as cardiovascular disease, diabetes or cancer. Despite that, methylated DNA presents a new generation of biomarkers, which brings a promising alternative for using in point-care diagnostic. Regarding this fact, DNA based electrochemical sensors enable fast, reliable, low-cost, time-consuming and efficient detection. The application of these biosensors as possible alternatives for the determination of methylated DNA is recently growing. Therefore, a biosensor for the determination of methylated DNA was fabricated. This study was aimed to develop an efficient biosensor, with an amplified electrochemical signal which is suited for the detection of the low-level concentration of methylated DNA. The bare gold electrode was first covered with the graphene oxide modified with gold, silver and copper nanoparticles. These composites have a strong affinity to DNA probe and their effect on the sensitivity and selectivity of the biosensor was investigated. The developed biosensor shows promising analytical characteristics with a wide detection linear range. The electrochemical impedance spectroscopy (EIS) was used to detect the hybridization of the DNA probe with methylated DNA target.

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Yu, Zhixue, Hui Wang, Yiguang Zhao, Fan Zhang, Xiangfang Tang, and Benhai Xiong. "Electrochemical Biosensor Using Nitrogen-Doped Graphene/Au Nanoparticles/DNAzyme for Ca2+ Determination." Biosensors 12, no. 5 (May 12, 2022): 331. http://dx.doi.org/10.3390/bios12050331.

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An electrochemical biosensor for detecting Ca2+ concentration was proposed using glass carbon electrodes (GCEs) modified with nitrogen-doped graphene (NGR), gold nanoparticles (AuNPs) and DNAzyme. The resistance signal was amplified through two methods: electrochemical reduction of AuNPs on the NGR surface to increase the specific surface area of the electrode and strengthen the adsorption of DNAzyme; and increasement of the DNAzyme base sequence. The process of electrode modification was characterized by scanning electron microscopy, Raman spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Experimental parameters’ influence, such as the deposition time of gold nanoparticles and the detection time, were assessed by electrochemical methods. The linear ranges of the electrochemical biosensor were in the range from 5 × 10−6 to 5 × 10−5 and 5 × 10−5 to 4 × 10−4 M, with a detection limit of 3.8 × 10−6 M. The concentration of Ca2+ in the serum of dairy cows was determined by the biosensor with satisfactory results, which could be potentially used to diagnose subclinical hypocalcemia.

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Huang, Zhiheng, Chunchuan Gu, Jiajun Wen, Langlang Zhu, Mingzhen Zhang, and Hongying Liu. "One-Pot Electrodeposition of NiS Nanoparticles as an Efficient Electrode for Nonenzymatic H2O2 and Glucose Sensors." Nano 14, no. 01 (January 2019): 1950010. http://dx.doi.org/10.1142/s1793292019500103.

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In this paper, a new and one-pot electrodeposition method was expanded for the preparation of NiS nanoparticles-based electrochemical biosensor using metal-ion complexes as a precursor. Thioacetamide was used to control the production rate of NiS nanoparticles for the first time. The proposed electrochemical sensor was characterized by energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FESEM), cyclic voltammograms (CV), and electrochemical impedance spectra (EIS). Experiment parameters were optimized. Under the optimized condition, the prepared NiS-based biosensor exhibited excellent electrocatalytic oxidation of H2O2 and glucose due to their small size. It provided fast and sensitive strategy for detecting H2O2 and glucose in the range of 1–5000 and 1–1000[Formula: see text][Formula: see text]M. The detection limit of 0.257 and 0.3[Formula: see text][Formula: see text]M was obtained for H2O2 and glucose. The mechanisms were also analyzed. The proposed biosensor exhibited excellent anti-interference and repeatability. Furthermore, it was applied in the actual sample analysis, such as human blood serum.

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Negahdary, Masoud, Mahnaz Jafarzadeh, Roya Rahimzadeh, Ghasem Rahimi, and Hamideh Dehghani. "A DNA biosensor for molecular diagnosis of <i>Aeromonas hydrophila</i> using zinc sulfide nanospheres." Journal of Sensors and Sensor Systems 6, no. 2 (July 27, 2017): 259–67. http://dx.doi.org/10.5194/jsss-6-259-2017.

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Abstract. Today, identification of pathogenic bacteria using modern and accurate methods is inevitable. Integration in electrochemical measurements with nanotechnology has led to the design of efficient and sensitive DNA biosensors against bacterial agents. Here, efforts were made to detect Aeromonas hydrophila using aptamers as probes and zinc sulfide (ZnS) nanospheres as signal enhancers and electron transfer facilitators. After modification of the working electrode area (in a screen-printed electrode) with ZnS nanospheres through electrodeposition, the coated surface of a modified electrode with ZnS nanospheres was investigated through scanning electron microscopy (SEM). The size of synthesized ZnS nanospheres was estimated at about 20–50 nm and their shape was in the form of porous plates in microscopic observations. All electrochemical measurements were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and constant potential amperometry (CPA) techniques. The designed DNA biosensor was able to detect deoxyribonucleic acid (DNA) of Aeromonas hydrophila in the range 1.0 × 10−4 to 1.0 × 10−9 mol L−1; the limit of detection (LOD) in this study was 1 × 10−13 mol L−1. This DNA biosensor showed satisfactory thermal and pH stability. Reproducibility for this DNA biosensor was measured and the relative standard deviation (RSD) of the performance of this DNA biosensor was calculated as 5 % during 42 days.

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Maâtouk, Ferdaous, Mouna Maâtouk, Karima Bekir, Houcine Barhoumi, Abderrazak Maaref, and Hedi Ben Mansour. "An electrochemical DNA biosensor for trace amounts of mercury ion quantification." Journal of Water and Health 14, no. 5 (May 27, 2016): 808–15. http://dx.doi.org/10.2166/wh.2016.293.

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In this work we report the development of an electrochemical DNA biosensor with high sensitivity for mercury ion detection. A new matrix based on gold nanoparticles (AuNPs)-glutathione (GSH)/cysteine was investigated. The interaction between DNA oligonucleotides and Hg2+ ions followed by the formation of Thymine–Hg2+–Thymine (T–Hg2+–T) structures was quantified using different electrochemical methods. It has been shown that the electrochemical impedance spectroscopy (EIS) measurements and the differential pulse voltammetry (DPV) confirmed the specific interaction between the oligonucleotide receptor layer and the Hg2+ ions. Besides, the developed sensor exhibited high sensitivity towards mercury among some examined metal ions such as Pb2+, Cu2+ and Cd2+. As a result, a high electrochemical response and low detection limit of 50 pM were estimated in the case of Hg2+ ions. The developed DNA biosensor was applied successfully to the determination of Hg2+ions in wastewater samples.

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Zhang, Yuzhong, Zhen Wang, Yuehong Wang, Lei Huang, Wei Jiang, and Mingzhu Wang. "Electrochemical Detection of Sequence-Specific DNA with the Amplification of Gold Nanoparticles." International Journal of Electrochemistry 2011 (2011): 1–7. http://dx.doi.org/10.4061/2011/619782.

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A sensitive electrochemical DNA biosensor was prepared based on mercaptoacetic acid (MAA)/gold nanoparticles (AuNPs) modified electrode. Probe DNA (NH2-DNA) was covalently linked to the carboxyl group of MAA in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxyl-succinimide (NHS). Scanning electron microscopy (SEM) and electrochemical impedance spectra (EIS) were used to investigate the film assembly process. The DNA hybridization events were monitored by differential pulse voltammetry (DPV), and adriamycin was used as the electrochemical indicator. Also the factors influencing the performance of the DNA hybridization were investigated in detail. Under the optimal conditions, the signal was linearly changed with target DNA concentration increased from 5.0 × 10−13to 1.0 × 10−9 M and had a detection limit of 1.7 × 10−13 M (signal/noise ratio of 3). In addition, the DNA biosensor showed good reproducibility and stability during DNA assay.

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Rozman, Martin, Zala Štukovnik, Ajda Sušnik, Amirhossein Pakseresht, Matej Hočevar, Damjana Drobne, and Urban Bren. "A HepG2 Cell-Based Biosensor That Uses Stainless Steel Electrodes for Hepatotoxin Detection." Biosensors 12, no. 3 (March 4, 2022): 160. http://dx.doi.org/10.3390/bios12030160.

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Humans are frequently exposed to environmental hepatotoxins, which can lead to liver failure. Biosensors may be the best candidate for the detection of hepatotoxins because of their high sensitivity and specificity, convenience, time-saving, low cost, and extremely low detection limit. To investigate suitability of HepG2 cells for biosensor use, different methods of adhesion on stainless steel surfaces were investigated, with three groups of experiments performed in vitro. Cytotoxicity assays, which include the resazurin assay, the neutral red assay (NR), and the Coomassie Brilliant Blue (CBB) assay, were used to determine the viability of HepG2 cells exposed to various concentrations of aflatoxin B1 (AFB1) and isoniazid (INH) in parallel. The viability of the HepG2 cells on the stainless steel surface was quantitatively and qualitatively examined with different microscopy techniques. A simple cell-based electrochemical biosensor was developed by evaluating the viability of the HepG2 cells on the stainless steel surface when exposed to various concentrations of AFB1 and INH by using electrochemical impedance spectroscopy (EIS). The results showed that HepG2 cells can adhere to the metal surface and could be used as part of the biosensor to determine simple hepatotoxic samples.

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Kumar, Neeraj, Shalu Yadav, Mohd Abubakar Sadique, and Raju Khan. "Electrochemically Exfoliated Graphene Quantum Dots Based Biosensor for CD44 Breast Cancer Biomarker." Biosensors 12, no. 11 (November 3, 2022): 966. http://dx.doi.org/10.3390/bios12110966.

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An innovative electrochemical biosensor based on graphene quantum dots (GQDs) is developed for a simple, rapid, and highly sensitive primary diagnosis of the breast cancer biomarker cluster of differentiation-44 (CD44) antigen. Herein, electrochemical exfoliation of waste dry batteries provides facile, eco-friendly, and cost-effective synthesis of GQDs. Transmission electron microscopy (TEM) analysis reveals that GQDs exhibit spherical shapes with an average diameter of 4.75 nm. Further, electrochemical analysis through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) reveals that the electrochemical properties of GQDs are suitable for biosensing applications. Subsequently, GQDs have a large electroactive surface area that has been utilized for the immobilization of CD44 antibodies to fabricate the electrochemical biosensor. The electroanalytical performance of GQDs for CD44 biosensing capabilities is studied by differential pulse voltammetry (DPV). The developed electrochemical biosensor has high sensitivity with the lowest detection limit (LOD) of 2.11 fg/mL in the linear range of 0.1 pg/mL to 100.0 ng/mL in phosphate buffer saline (PBS). Further, the linear response of the electrochemical biosensor for CD44 antigen concentration is in the range of 1.0 pg/mL to 100.0 ng/mL with a LOD of 2.71 fg/mL in spiked serum samples. The outcomes suggest that the synthesized GQDs demonstrate promising attributes to be utilized as a viable nanomaterial in biosensing applications.

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Marrugo-Ramírez, Jose, Montserrat Rodríguez-Núñez, M. Pilar Marco, Mónica Mir, and Josep Samitier. "Kynurenic Acid Electrochemical Immunosensor: Blood-Based Diagnosis of Alzheimer’s Disease." Biosensors 11, no. 1 (January 12, 2021): 20. http://dx.doi.org/10.3390/bios11010020.

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Alzheimer’s disease (AD) is a neurodegenerative disorder, characterized by a functional deterioration of the brain. Currently, there are selected biomarkers for its diagnosis in cerebrospinal fluid. However, its extraction has several disadvantages for the patient. Therefore, there is an urgent need for a detection method using sensitive and selective blood-based biomarkers. Kynurenic acid (KYNA) is a potential biomarker candidate for this purpose. The alteration of the KYNA levels in blood has been related with inflammatory processes in the brain, produced as a protective function when neurons are damaged. This paper describes a novel electrochemical immunosensor for KYNA detection, based on successive functionalization multi-electrode array. The resultant sensor was characterized by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The proposed biosensor detects KYNA within a linear calibration range from 10 pM to 100 nM using CA and EIS, obtaining a limit of detection (LOD) of 16.9 pM and 37.6 pM in buffer, respectively, being the lowest reported LOD for this biomarker. Moreover, to assess our device closer to the real application, the developed immunosensor was also tested under human serum matrix, obtaining an LOD of 391.71 pM for CA and 278.8 pM for EIS with diluted serum.

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Chiriacò, Maria, Ilaria Parlangeli, Fausto Sirsi, Palmiro Poltronieri, and Elisabetta Primiceri. "Impedance Sensing Platform for Detection of the Food Pathogen Listeria monocytogenes." Electronics 7, no. 12 (November 23, 2018): 347. http://dx.doi.org/10.3390/electronics7120347.

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A great improvement in food safety and quality controls worldwide has been achieved through the development of biosensing platforms. Foodborne pathogens continue to cause serious outbreaks, due to the ingestion of contaminated food. The development of new, sensitive, portable, high-throughput, and automated platforms is a primary objective to allow detection of pathogens and their toxins in foods. Listeria monocytogenes is one common foodborne pathogen. Major outbreaks of listeriosis have been caused by a variety of foods, including milk, soft cheeses, meat, fermented sausages, poultry, seafood and vegetable products. Due to its high sensitivity and easy setup, electrochemical impedance spectroscopy (EIS) has been extensively applied for biosensor fabrication and in particular in the field of microbiology as a mean to detect and quantify foodborne bacteria. Here we describe a miniaturized, portable EIS platform consisting of a microfluidic device with EIS sensors for the detection of L. monocytogenes in milk samples, connected to a portable impedance analyzer for on-field application in clinical and food diagnostics, but also for biosecurity purposes. To achieve this goal microelectrodes were functionalized with antibodies specific for L. monocytogenes. The binding and detection of L. monocytogenes was achieved in the range 2.2 × 103 cfu/mL to 1 × 102 with a Limit of Detection (LoD) of 5.5 cfu/mL.

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Molinnus, Denise, Stefan Beging, Carsten Lowis, and Michael J. Schöning. "Towards a Multi-Enzyme Capacitive Field-Effect Biosensor by Comparative Study of Drop-Coating and Nano-Spotting Technique." Sensors 20, no. 17 (August 31, 2020): 4924. http://dx.doi.org/10.3390/s20174924.

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Multi-enzyme immobilization onto a capacitive field-effect biosensor by nano-spotting technique is presented. The nano-spotting technique allows to immobilize different enzymes simultaneously on the sensor surface with high spatial resolution without additional photolithographical patterning. The amount of applied enzymatic cocktail on the sensor surface can be tailored. Capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensors with Ta2O5 as pH-sensitive transducer layer have been chosen to immobilize the three different (pL droplets) enzymes penicillinase, urease, and glucose oxidase. Nano-spotting immobilization is compared to conventional drop-coating method by defining different geometrical layouts on the sensor surface (fully, half-, and quarter-spotted). The drop diameter is varying between 84 µm and 102 µm, depending on the number of applied drops (1 to 4) per spot. For multi-analyte detection, penicillinase and urease are simultaneously nano-spotted on the EIS sensor. Sensor characterization was performed by C/V (capacitance/voltage) and ConCap (constant capacitance) measurements. Average penicillin, glucose, and urea sensitivities for the spotted enzymes were 81.7 mV/dec, 40.5 mV/dec, and 68.9 mV/dec, respectively.

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Chou, Jung-Chuan, Si-Hong Lin, Tsu-Yang Lai, Po-Yu Kuo, Chih-Hsien Lai, Yu-Hsun Nien, and Tzu-Yu Su. "A Facile Fabrication of a Potentiometric Arrayed Glucose Biosensor Based on Nafion-GOx/GO/AZO." Sensors 20, no. 4 (February 11, 2020): 964. http://dx.doi.org/10.3390/s20040964.

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In this study, the potentiometric arrayed glucose biosensors, which were based on zinc oxide (ZnO) or aluminum-doped zinc oxide (AZO) sensing membranes, were fabricated by using screen-printing technology and a sputtering system, and graphene oxide (GO) and Nafion-glucose oxidase (GOx) were used to modify sensing membranes by using the drop-coating method. Next, the material properties were characterized by using a Raman spectrometer, a field-emission scanning electron microscope (FE-SEM), and a scanning probe microscope (SPM). The sensing characteristics of the glucose biosensors were measured by using the voltage–time (V-T) measurement system. Finally, electrochemical impedance spectroscopy (EIS) was conducted to analyze their charge transfer abilities. The results indicated that the average sensitivity of the glucose biosensor based on Nafion-GOx/GO/AZO was apparently higher than that of the glucose biosensor based on Nafion-GOx/GO/ZnO. In addition, the glucose biosensor based on Nafion-GOx/GO/AZO exhibited an excellent average sensitivity of 15.44 mV/mM and linearity of 0.997 over a narrow range of glucose concentration range, a response time of 26 s, a limit of detection (LOD) of 1.89 mM, and good reproducibility. In terms of the reversibility and stability, the hysteresis voltages (VH) were 3.96 mV and 2.42 mV. Additionally, the glucose biosensor also showed good anti-inference ability and reproducibility. According to these results, it is demonstrated that AZO is a promising material, which could be used to develop a reliable, simple, and low-cost potentiometric glucose biosensor.

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Chiticaru, Elena A., Luisa Pilan, Celina-Maria Damian, Eugeniu Vasile, Jorge S. Burns, and Mariana Ioniţă. "Influence of Graphene Oxide Concentration when Fabricating an Electrochemical Biosensor for DNA Detection." Biosensors 9, no. 4 (September 26, 2019): 113. http://dx.doi.org/10.3390/bios9040113.

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We have investigated the influence exerted by the concentration of graphene oxide (GO) dispersion as a modifier for screen printed carbon electrodes (SPCEs) on the fabrication of an electrochemical biosensor to detect DNA hybridization. A new pretreatment protocol for SPCEs, involving two successive steps in order to achieve a reproducible deposition of GO, is also proposed. Aqueous GO dispersions of different concentrations (0.05, 0.1, 0.15, and 0.2 mg/mL) were first drop-cast on the SPCE substrates and then electrochemically reduced. The electrochemical properties of the modified electrodes were investigated after each modification step by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), while physicochemical characterization was performed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Finally, the sensing platform was obtained by the simple adsorption of the single-stranded DNA probe onto the electrochemically reduced GO (RGO)-modified SPCEs under optimized conditions. The hybridization was achieved by incubating the functionalized SPCEs with complementary DNA target and detected by measuring the change in the electrochemical response of [Fe(CN)6]3–/4– redox reporter in CV and EIS measurements induced by the release of the newly formed double-stranded DNA from the electrode surface. Our results showed that a higher GO concentration generated a more sensitive response towards DNA detection.

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Işın, Deniz, Ece Eksin, and Arzum Erdem. "Graphene-Oxide and Ionic Liquid Modified Electrodes for Electrochemical Sensing of Breast Cancer 1 Gene." Biosensors 12, no. 2 (February 4, 2022): 95. http://dx.doi.org/10.3390/bios12020095.

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Graphene-oxide and ionic liquid composite-modified pencil graphite electrodes (GO-IL-PGEs) were developed and used as a sensing platform for breast cancer 1 (BRCA1) gene detection. The characterization of GO-IL modified electrodes was executed by scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The nucleic-acid hybridization was monitored by a differential pulse voltammetry (DPV) technique by directly measuring the guanine oxidation signal without using any indicator. The effects of the IL concentration, the probe concentration, and the hybridization time were optimized to the biosensor response. The limit of detection (LOD) was calculated in the concentration range of 2–10 μg/mL for the BRCA1 gene and found to be 1.48 µg/mL. The sensitivity of the sensor was calculated as 1.49 µA mL/µg cm2. The developed biosensor can effectively discriminate the complementary target sequence in comparison to a three-base-mismatched sequence or the non-complementary one.

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Malik, Mansi, Reeti Chaudhary, and C. S. Pundir. "Construction of an Amperometric Pyruvate Biosensor Based on Enzyme Bound to A Nanocomposite and Its Comparison with Enzyme Nanoparticles Bound to Electrode." International Journal of Applied Sciences and Biotechnology 7, no. 2 (June 14, 2019): 195–206. http://dx.doi.org/10.3126/ijasbt.v7i2.24445.

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An improved amperometric pyruvate biosensor was fabricated by immobilizing covalently commercial pyruvate oxidase (POx) from Aerococcus sps. onto nanocomposite of c-MWCNT (carboxylated multi- walled carbon nanotubes), copper nanoparticles (CuNPs) and polyaniline (PANI) electrodeposited onto gold (Au) electrode. The copper nanoparticles were prepared by chemical reduction method and characterized by transmission electron microscopy (TEM), UV- visible spectroscopy and X- ray diffraction (XRD). The working electrode (POx/c-MWCNT/CuNPs/PANI/AuE was studied via scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and electrochemical impedance spectroscopy (EIS) at different stages of its construction. The biosensor showed optimum activity at a pH of 5.0 and 35°C and a linearity for pyruvate in the concentration range, 0.1 µM to 2000 µM. The analytical recovery of added pyruvate was 99.6% and 99.2%. The within and between batch coefficients of variation (CV) were 0.052% and as 0.022% respectively. There was a commendable correlation between sera pyruvate values as measured by standard spectrophotometric method and the present method. The biosensor was applied to measure sera pyruvate level and compared with that biosensor based on pyruvate oxidase nanoparticles covalently bound to Au electrode. Malik et al. (2019) Int. J. Appl. Sci. Biotechnol. Vol 7(2): xxx-xxx Graphic Abstract Schematic representation of fabrication of POx/c-MWCNTs/CuNPs/PANI/AuE and electrochemical reactions involved in its response measurement (POx- Pyruvate oxidase; c-MWCNTs- Carboxylated multi-walled carbon nanotubes; CuNPs- Copper nanoparticles; PANI- Polyaniline; AuE- Gold electrode).

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Li, Feng, Jian Fei Xia, Zong Hua Wang, Yan Zhi Xia, Fei Fei Zhang, and Lin Hua Xia. "Graphene Modified Molecular Imprinted Electrochemical Sensor for Specific Recognition of Bovine Serum Albumin." Advanced Materials Research 709 (June 2013): 891–94. http://dx.doi.org/10.4028/www.scientific.net/amr.709.891.

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A simple and efficient molecularly imprinted sensor (MIPs/GR/GCE) was firstly prepared by electropolymerization of pyrrole in the presence of bovine serum albumin (BSA) in an aqueous solution based on a graphene modified glassy carbon electrode for the selective recognition of bovine serum albumin. The prepared sensor was characterized by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS), in which [Fe(CN)6]3−/4−was used as an electrochemical active probe. The results showed a wide linear range from 1.0 × 10-3to 1.0 × 10-9g/mL. And the imprinted biosensor indicated excellent selectivity and high sensitivity.

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Sun, Ying Ying, Shuang Zhao, and Qun Xiang Ren. "Glucose Biosensor Based on Immobilization of Glucose Oxidase on Silica Nanoparticles Modified Au Electrode." Advanced Materials Research 503-504 (April 2012): 424–27. http://dx.doi.org/10.4028/www.scientific.net/amr.503-504.424.

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A feasible method to fabricate glucose biosensor was developed by covalent attachment of glucose oxidase (GOx) to a silica nanoparticle monolayer modified gold electrode. Electrochemical impedance spectroscopy (EIS) of ferrocyanide followed the assembly process and verified the successful immobilization of GOx on silica nanoparticle modified on gold electrodes. Cyclic voltammetry (CV), performed in the presence of excess glucose and artificial redox mediator (ferrocenemethanol), allowed to quantify the surface concentration of electrically wired enzyme. The signal of proposed electrode was more than 2.5 times of that on electrode lacking silica nanoparticles. As a result, silica nanoparticles are a good biocompatible solid support for enzyme immobilization.

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37

P.H. Hutapea, T., Rukisah ., Mulyadi ., K. A. Madurani, Suprapto ., and F. Kurniawan. "Milkfish (Chanos Chanos) Gelatin as Biosensor Material for Chromium (III) Detection." International Journal of Engineering & Technology 7, no. 4.14 (December 24, 2019): 227. http://dx.doi.org/10.14419/ijet.v7i4.14.27570.

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Milkfish (Chanos chanos) gelatin was successfully developed as biosensor material. The milkfish bone was obtained from local restaurants in Tarakan, North Borneo, Indonesia. Gelatin was extracted from milkfish bone using acid method at 55°C. Characterization by FTIR showed that milkfish gelatin had similar functional group with commercial gelatin. The gelatin was used as biosensor material for detecting chromium. The gelatin was mixed with carbon in 1:1 ratio to form gelatin/carbon paste modified silver electrode. Electrochemical impedance spectroscopy (EIS) analysis of the gelatin/carbon paste modified silver electrode showed a better conductivity than paraffin/carbon paste modified silver electrode. Performance of the gelatin/carbon paste modified silver electrode in chromium (III) solution was conducted using cyclic voltammetry technique. Measurement was carried out at -1 V to +1 V with scan rate of 100 mV/s in acid and base condition. The best result was shown by gelatin/carbon paste modified silver electrode. It can detect chromium (III) ions at reduction potential of -0.78 V in alkaline condition. Unspecific responses were observed from silver electrode, paraffin/silver electrode, carbon/silver electrode, gelatin/silver electrode and paraffin/carbon paste modified silver electrode. This result can be concluded that the milkfish gelatin obtained have a potential to be developed as chromium (III) biosensor.

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Adriano Dorledo de Faria, Ricardo, Manuel Houmard, Verônica Aparecida Martins do Rosário, Vanessa de Freitas Cunha Lins, Luiz Guilherme Dias Heneine, and Tulio Matencio. "TiO2 Sol-gel Coating as a Transducer Substrate for Impedimetric Immunosensors." Chemical & biochemical engineering quarterly 33, no. 4 (2020): 437–47. http://dx.doi.org/10.15255/cabeq.2019.1699.

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Given the importance of the transducer elements in the performance of sensors for various applications, as well as the growing search for devices that are capable of providing the response in shorter time, in this work, titanium dioxide was examined as a candidate for application in an electrochemical biosensor. A TiO2 coating deposited by sol-gel method on a silicon wafer was obtained with an anatase crystalline structure, as an n-type<br /> semiconductor with donor density equal to 2.954 · 1017 cm–3. Its surface was functionalized to be tested as a biosensor to detect snake venom of the Bothrops genera, and each step of the functionalization was investigated using Electrochemical Impedance Spectroscopy (EIS) and Cyclic voltammetry. Despite being less sensitive than the reference method ELISA, the TiO2-based biosensor was also capable of detecting the analyte of interest at 20 μg mL–1, revealing an increase in its leakage resistance and phase shift after incubation in this solution. Furthermore, the total time for carrying out the biodetection with the TiO2-coated device (41.24 ± 0.05 min) was estimated to be approximately 80 % shorter than that required by the labelled standard assay, which indicates that TiO2 is a promising electrochemical transducer for biosensing applications.

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Uludağ, İnci, and Mustafa Kemal Sezgintürk. "Ultrasensitive and Cost-Effective Detection of Neuropeptide-Y by a Disposable Immunosensor: A New Functionalization Route for Indium-Tin Oxide Surface." Biosensors 12, no. 11 (October 26, 2022): 925. http://dx.doi.org/10.3390/bios12110925.

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Neuropeptide Y (NPY) is one of the most abundant neuropeptides in the human brain, and its levels in the blood change in neurodegenerative and neuroimmune disorders. This indicates that NPY may serve as a diagnostic and monitoring marker for associated disorders. In this paper, an electrochemical immunosensor was created to detect NPY biomarkers using a novel immobilization technique. The proposed biosensor system enables accurate, specific, cost-effective, and practical biomarker analysis. Indium tin oxide-coated polyethylene terephthalate (ITO-PET) sheets were treated with hexamethylene diisocyanate (HMDC) to covalently immobilize antibodies. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques were used to analyze each step of the biosensors. The proposed NPY biosensor has a broad linear detection range (0.01–100 pg mL−1), a low limit of detection (LOD) (0.02968 pg mL−1), and a low limit of quantification (LOQ) (0.0989 pg mL−1). Atomic force microscopy (AFM) was used to support in the optimization process, study the surface morphology, and visualize it. Studies of repeatability, reproducibility, storage, and Kramers–Kronig transformation were conducted during electrochemical characterization. After analytical experiments, the biosensor’s responses to human serum samples were evaluated. According to the obtained data, the error margin is small, and the created biosensor offers a great deal of promise for the clinical measurement of NPY.

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Blaškovičová, Jana, Vlastimil Vyskočil, Michal Augustín, and Andrea Purdešová. "Ethanol and NaCl-Induced Gold Nanoparticle Aggregation Toxicity toward DNA Investigated with a DNA/GCE Biosensor." Sensors 23, no. 7 (March 24, 2023): 3425. http://dx.doi.org/10.3390/s23073425.

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Engineered nanomaterials are becoming increasingly common in commercial and consumer products and pose a serious toxicological threat. Exposure of human organisms to nanomaterials can occur by inhalation, oral intake, or dermal transport. Together with the consumption of alcohol in the physiological environment of the body containing NaCl, this has raised concerns about the potentially harmful effects of ingested nanomaterials on human health. Although gold nanoparticles (AuNPs) exhibit great potential for various biomedical applications, there is some inconsistency in the case of the unambiguous genotoxicity of AuNPs due to differences in their shape, size, solubility, and exposure time. A DNA/GCE (DNA/glassy carbon electrode) biosensor was used to study ethanol (EtOH) and NaCl-induced gold nanoparticle aggregation genotoxicity under UV light in this study. The genotoxic effect of dispersed and aggregated negatively charged gold nanoparticles AuNP1 (8 nm) and AuNP2 (30 nm) toward salmon sperm double-stranded dsDNA was monitored by cyclic and square-wave voltammetry (CV, SWV). Electrochemical impedance spectroscopy (EIS) was used for a surface study of the biosensor. The aggregation of AuNPs was monitored by UV-vis spectroscopy. AuNP1 aggregates formed by 30% v/v EtOH and 0.15 mol·L−1 NaCl caused the greatest damage to the biosensor DNA layer.

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Turek, Monika, Lothar Ketterer, Melanie Claßen, Heinz Berndt, Gereon Elbers, Peter Krüger, Michael Keusgen, and Michael Schöning. "Development and Electrochemical Investigations of an EIS- (Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection." Sensors 7, no. 8 (August 3, 2007): 1415–26. http://dx.doi.org/10.3390/s7081415.

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Kongsuphol, Patthara, Hui Hwee Ng, Joanna P. Pursey, Sunil K. Arya, Chee Chung Wong, Eugen Stulz, and Mi Kyoung Park. "EIS-based biosensor for ultra-sensitive detection of TNF-α from non-diluted human serum." Biosensors and Bioelectronics 61 (November 2014): 274–79. http://dx.doi.org/10.1016/j.bios.2014.05.017.

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Budvytyte, Rima, Akvile Milasiute, Dalius Vitkus, Kestutis Strupas, Aiste Gulla, Ieva Sakinyte, and Julija Razumiene. "Tethered Lipid Membranes as a Nanoscale Arrangement towards Non-Invasive Analysis of Acute Pancreatitis." Biomedicines 9, no. 7 (June 29, 2021): 755. http://dx.doi.org/10.3390/biomedicines9070755.

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Extracellular heat shock proteins (HSPs) mediate immunological functions and are involved in pathologies such as infection, stress, and cancer. Here, we demonstrated the dependence of an amount of HSP70 and HSP90 in serum vs. severity of acute pancreatitis (AP) on a cohort of 49 patients. Tethered bilayer lipid membranes (tBLMs) have been developed to investigate HSPs’ interactions with tBLMs that can be probed by electrochemical impedance spectroscopy (EIS). The results revealed that HSP70 and HSP90 interact via different mechanisms. HSP70 shows the damage of the membrane, while HSP90 increases the insulation properties of tBLM. These findings provide evidence that EIS offers a novel approach for the study of the changes in membrane integrity induced by HSPs proteins. Herein, we present an alternative electrochemical technique, without any immunoprobes, that allows for the monitoring of HSPs on nanoscaled tBLM arrangement in biologics samples such us human urine. This study demonstrates the great potential of tBLM to be used as a membrane based biosensor for novel, simple, and non-invasive label-free analytical system for the prediction of AP severity.

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Chornokur, Ganna, Sunil K. Arya, Catherine Phelan, Richard Tanner, and Shekhar Bhansali. "Impedance-Based Miniaturized Biosensor for Ultrasensitive and Fast Prostate-Specific Antigen Detection." Journal of Sensors 2011 (2011): 1–7. http://dx.doi.org/10.1155/2011/983752.

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This paper reports the successful fabrication of an impedance-based miniaturized biosensor and its application for ultrasensitive Prostate-Specific Antigen (PSA) detection in standard and real human plasma solution, spiked with different PSA concentrations. The sensor was fabricated using photolithographic techniques, while monoclonal antibodies specific to human PSA were used as primary capture antibodies. Electrochemical impedance spectroscopy (EIS) was employed as a detection technique. The sensor exhibited a detection limit of 1 pg/ml for PSA with minimal nonspecific binding (NSB). This detection limit is an order of magnitude lower than commercial PSA ELISA assays available on the market. The sensor can be easily modified into an array for the detection of other biomolecules of interest, enabling accurate, ultrasensitive, and inexpensive point-of-care sensing technologies.

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Alsabbagh, Khaled, Tim Hornung, Achim Voigt, Sahba Sadir, Taleieh Rajabi, and Kerstin Länge. "Microfluidic Impedance Biosensor Chip with DNA-Based Self-Assembled Monolayers for Label-Free Detection of Cardiac Biomarker Troponin I." Proceedings 60, no. 1 (November 2, 2020): 38. http://dx.doi.org/10.3390/iecb2020-07033.

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A microfluidic chip for electrochemical impedance spectroscopy (EIS) is presented as biosensor for the detection of cardiac troponin I (cTnI). Troponin I is one of the most specific diagnostic serum biomarkers for myocardial infarction. As impedimetric biosensors allow direct and label-free analyte detection, they are particularly suitable for fast biomarker detection. This is essential in the diagnosis of cardiac infarctions to enable an early treatment promoting a positive outcome. The microfluidic impedance biosensor chip presented here consists of a microscope glass slide serving as base plate, sputtered electrodes, and a polydimethylsiloxane (PDMS) microchannel. Electrode functionalization protocols were developed considering a low initial impedance in addition to analyte-specific binding by corresponding antibodies and reduction of non-specific protein adsorption to prevent false-positive signals. Reagents tested for self-assembled monolayers (SAMs) on gold electrodes included thiolated hydrocarbons and thiolated oligonucleotides, where SAMs based on the latter showed a better performance. The corresponding antibody (anti-cTnI) was covalently coupled on the SAM using carbodiimide chemistry. The PDMS microchannel was bonded on the glass slide with the functionalized electrodes, and the completed microfluidic impedance biosensor chip was connected to the readout system. Sampling and measurement took only a few minutes. Application of a human serum albumin (HSA) sample, 1000 ng/mL, led to negligible signal changes, while application of a troponin I sample, 1 ng/mL, led to a significant signal shift in the Nyquist plot. The results are promising regarding specific detection of clinically relevant concentrations of cardiac markers with the newly developed impedance biosensor chip.

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Lee, Taek, Jinmyeong Kim, Inho Nam, Yeonju Lee, Ha Eun Kim, Hiesang Sohn, Seong-Eun Kim, et al. "Fabrication of Troponin I Biosensor Composed of Multi-Functional DNA Structure/Au Nanocrystal Using Electrochemical and Localized Surface Plasmon Resonance Dual-Detection Method." Nanomaterials 9, no. 7 (July 11, 2019): 1000. http://dx.doi.org/10.3390/nano9071000.

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In the present study, we fabricated a dual-mode cardiac troponin I (cTnI) biosensor comprised of multi-functional DNA (MF-DNA) on Au nanocrystal (AuNC) using an electrochemical method (EC) and a localized surface plasmon resonance (LSPR) method. To construct a cTnI bioprobe, a DNA 3 way-junction (3WJ) was prepared to introduce multi-functionality. Each DNA 3WJ arm was modified to possess a recognition region (Troponin I detection aptamer), an EC-LSPR signal generation region (methylene blue: MB), and an anchoring region (Thiol group), respectively. After an annealing step, the multi-functional DNA 3WJ was assembled, and its configuration was confirmed by Native-TBM PAGE for subsequent use in biosensor construction. cTnI was also expressed and purified for use in biosensor experiments. To construct an EC-LSPR dual-mode biosensor, AuNCs were prepared on an indium-tin-oxide (ITO) substrate using an electrodeposition method. The prepared multi-functional (MF)-DNA was then immobilized onto AuNCs by covalent bonding. Field emission scanning electron microscope (FE-SEM) and atomic force microscopy (AFM) were used to analyze the surface morphology. LSPR and electrochemical impedance spectroscopy (EIS) experiments were performed to confirm the binding between the target and the bioprobe. The results indicated that cTnI could be effectively detected in the buffer solution and in diluted-human serum. Based on the results of these experiments, the loss on drying (LOD) was determined to be 1.0 pM in HEPES solution and 1.0 pM in 10% diluted human serum. Additionally, the selectivity assay was successfully tested using a number of different proteins. Taken together, the results of our study indicate that the proposed dual-mode biosensor is applicable for use in field-ready cTnI diagnosis systems for emergency situations.

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VATTIPALLI, KRISHNA, PAIGE FEIKERT, SAVINDRA BRANDIGAMPALA, and SHALINI PRASAD. "STUDY OF NANOPOROUS MEMBRANES WITH APPLICATIONS IN THE ENHANCED DETECTION OF CADIOVASCULAR BIOMARKER PROTEINS." Nano LIFE 01, no. 03n04 (September 2010): 175–83. http://dx.doi.org/10.1142/s1793984410000213.

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The goal of this work is to understand the role of nanoconfinement in designing molecular biosensors. We have been investigating microdevices incorporated with nanoporous membranes as molecular biosensor platforms. Detection of ultra low concentration of biomolecules is the key expectation from the new class of molecular biosensors utilizing nanomaterial. In this paper we have evaluated the role of the physical attributes of nanoporous aluminum oxide membranes in nanoconfinement and enhancing sensitivity of detection of protein biomolecules. In this biosensor configuration we have generated a sandwich assay in a high density array of nanoscale confined spaces generated by overlaying the nanoporous alumina membrane over metallic microscale sensing sites. The binding of the biomolecules results in the perturbation of the electrical double layer due to the binding of the test protein (C-reactive protein). Using electrical impedance spectroscopy (EIS), the capacitance changes in the electrical double layer associated with specific protein binding has been evaluated. The sensor performance metrics of sensitivity and dynamic range have been analyzed with changes in the pore diameter.

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Kannan, Bhuvaneswari, David E. Williams, and Jadranka Travas-Sejdic. "Effect of Morphology of Conducting Polymer on DNA Sensing." Materials Science Forum 700 (September 2011): 211–14. http://dx.doi.org/10.4028/www.scientific.net/msf.700.211.

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Electrochemical DNA sensors can be constructed by understanding basic interfacial electron transfer between solid surface-electrolyte-DNA interfaces. The kinetics of this heterogeneous process can be significantly affected by the microstructure and roughness of the electrode surface. By understanding this concept, in this paper; we compared the performance of micro electrodes containing poly(Py-co-PAA) with macro electrode containing same copolymer, showing that micro electrodes are more sensitive than the macro electrodes for biosensor applications. Sensors based on the copolymer electropolymerised on both micro and macro electrodes were evaluated across a range of oligonucleotide concentrations. The interfacial electron charge transfer resistance between the solution and electrode surface was studied using electrochemical impedance spectroscopy (EIS).

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Lin, Cheng, Man Fang Mai, Zhao Xian Xiong, Hao Xue, and Hong Qiu. "Preparation and Performance of Polypyrrole Film with Micro-Antennal Morphology for Medical Biology." Materials Science Forum 610-613 (January 2009): 1096–103. http://dx.doi.org/10.4028/www.scientific.net/msf.610-613.1096.

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PPy film with micro-antennal morphology was prepared by potentio-static method without any templates directly onto the surfaces of iron, platinum and gold-plated plastic sheets, respectively. Morphology of PPy film was observed with scanning electron microscopy, and its electrochemical properties were determined by means of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Attention was paid to the influence of reaction time, potential value, types of substrates, types and conconcentrations of electrolyte on the morphology and electrochemical properties of PPy film. Stable PPy film with thriftily long antennae was obtained on different substrates with good electrochemical properties. The film was applied for a prototype of biosensor, in which bioactive substance of glucose oxidase was immobilized.

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Song, Xin-Yan, Xin Meng, Bao-Lin Xiao, Yang-Yang Li, Xin-Xin Ma, Ali Akbar Moosavi-Movahedi, and Jun Hong. "MWCNTs-CTAB and HFs-Lac Nanocomposite-Modified Glassy Carbon Electrode for Rutin Determination." Biosensors 12, no. 8 (August 11, 2022): 632. http://dx.doi.org/10.3390/bios12080632.

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Rutin is a flavonoid glycoside compound, which is mainly transported via the blood circulation system in the human body. The monitoring of the blood concentration of rutin is of great significance in many fields such as pharmacology and pharmacokinetics. In this work, a biosensor based on multi-walled carbon nanotubes (MWCNTs), cetyltrimethylammonium bromide (CTAB), hydroxyl fullerenes (HFs), and laccase (Lac) nanocomposite-modified glassy carbon electrodes was constructed. The modified materials were characterized with a transmission electron microscope (TEM), cyclic voltammograms (CV), and electrochemical impedance spectroscopy (EIS). CTAB is used to disperse MWCNTs and improve hydrophilicity and biocompatibility of MWCNTs, while the use of Lac can enhance the oxidation of catechol structure in rutin, thus significantly improving the sensitivity and selectivity of the modified electrode. Linear sweep voltammetry (LSV) studies showed that the determination linear ranges of rutin were 0.1 µmol L−1 to 2 µmol L−1 and 2 µmol L−1 to 11 µmol L−1, with the determination limits of 30 nmol L−1 and 95.5 nmol L−1, respectively. The proposed biosensor can be used to detect rutin tablets and serum samples with high recovery, which indicates a good accuracy of this method, and the results are consistent with those measured by the traditional ultra-high performance liquid chromatography (UHPLC) method. Hence, this biosensor has potential practical application value in rutin drug quality testing and clinical blood drug concentration monitoring.

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Journal articles on the topic 'EIS-biosensor'

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