Electrochemical Determination of Homocysteine at Disposable Graphite Electrodes

Abstract

In the case of disruption of Hcy metabolism, the blood level of Hcy increases and it causes particularly the cardiovascular diseases, cancer, dementia and Parkinson’s disease. Thus, the sensitive analysis of Hcy levels in biological fluids is very important. Hcy analysis was performed herein using very practical and cost‐effective protocol using differential pulse voltammetry and graphite electrode. Detection limit of Hcy was found to be 1.21 µM in the linear range from 2 µM to 20 µM. The electrochemical Hcy detection in artificial urine medium was also successfully performed even in the presence of L‐Cysteine, L‐Methionine and Glutathione.

Ionic Liquid Modified Single‐use Electrode Developed for Voltammetric Detection of miRNA‐34a and its Application to Real Samples

“…After modification of IL onto surface of CA-PGE, an increase at Ia was observed due to high conductivity of IL. This result is consistent with the ones presented in previous literatures [60,62,65,66,68,69]. Since the highest I a was obtained after the modification of 20 % IL onto the surface of CA-PGE of all (shown in Figure S3-B), it was chosen as the optimum IL ratio for further experiments in our study.…”

“…ILs have also been used in different fields such as batteries and capacitors, fuel cells, photovoltaics, extractions and separations [50][51][52][53][54][55], optical sensors [56,57] and electrochemical sensors [58]. The utilization of ILs as modifiers to surfaces of electrochemical sensor increases the sensitivity, stability and selectivity of the reduction and/or oxidation of chemical compounds [58][59][60][61][62].…”

A miniaturized electrochemical assay for homocysteine using screen-printed electrodes with cytochrome c anchored gold nanoparticles

“…† The maximum response was observed at pH 7.2 in both cases, indicating that the electrocatalytic response is controlled by the activity of cyt c. Furthermore, cyt c attached to the GNP-SPE (Fig. 48,49 HcySH oxidation occurs due to the electron release from the thiol group in the presence of an electron acceptor cyt c as shown in the following equation: This may be due to the better affinity of cyt c to the GNP than to carbon, resulting in immobilization of more cyt c. 46 An earlier reported strategy 47 indicates that cyt c shows its optimum activity at pH 7.0, hence, the present immobilization process does not strongly affect the catalytic function of cyt c. Prior to the addition of HcySH, no changes were observed on both surfaces, whereas after addition a clear oxidation peak was observed at the potential starting from +0.3 V and extending to +0.6 V, which is in agreement with earlier reports.…”

Nanofibers for Biomedical and Healthcare Applications

“…The specific affinity of DNA or PNA (peptide nucleic acid) for hybridization with its complementary strand has been used in the development of these biosensors . With these devices, some success has been reported for pathogenic microbe detection such as Escherichia coli O157:H7 and bovine viral diarrhea virus (BVDV), malarial parasites, Hepatitis B virus . Luo et al.…”

“…[184] With these devices, some success has been reported for pathogenic microbe detection such as Escherichia coli O157:H7 [185,186] and bovine viral diarrhea virus (BVDV), [185] malarial parasites, [187] Hepatitis B virus. [188] Luo et al used the electrospinning method to fabricate electrospun capture membrane made of nanofibrous nitrocellulose and its antibody functionalization (Figure 9a). [185] Electrospun-based biosensor on the capture membrane is designed by capillary immunoassay, direct-charge electrical measurement, and integrating magnetic separation, for rapid and quantitative detection of viral and bacterial pathogens ( Figure 9b).…”