Next Article in Journal
An Optical Fiber Sensor Based on La2O2S:Eu Scintillator for Detecting Ultraviolet Radiation in Real-Time
Previous Article in Journal
Amphiphilic Fluorine-Containing Block Copolymers as Carriers for Hydrophobic PtTFPP for Dissolved Oxygen Sensing, Cell Respiration Monitoring and In Vivo Hypoxia Imaging with High Quantum Efficiency and Long Lifetime
Open AccessArticle

Electroanalytical Determination of Cysteine Using the Electrodes Based on Ternary Silver-Copper Sulfides

1
Department of General and Inorganic Chemistry, Faculty of Chemistry and Technology, University of Split, 21000 Split, Croatia
2
Department of Environmental Chemistry, Faculty of Chemistry and Technology, University of Split, 21000 Split, Croatia
3
Faculty of Chemistry and Technology, University of Split, 21000 Split, Croatia
*
Author to whom correspondence should be addressed.
Sensors 2018, 18(11), 3753; https://doi.org/10.3390/s18113753
Received: 7 October 2018 / Revised: 29 October 2018 / Accepted: 31 October 2018 / Published: 2 November 2018
(This article belongs to the Section Chemical Sensors)
The amperometric determination of cysteine, using an electrode based on ternary silver-copper sulfide, is presented. Electrochemical characterizations (using cyclic voltammetry) of three electrode materials revealed that the electrode based on the material that consists of jalpaite (Ag3CuS2), doped with a small amount of metallic silver, has the best electrocatalytical performance for cysteine oxidation. For the amperometric determination, 0.142 V at pH 5 and 0.04 V at pH 7 vs. Ag/AgCl, related to the electrocatalytical oxidation of thiol group, were chosen. Electrochemical impedance spectroscopy together with Fourier transform infrared spectroscopy (FTIR) revealed that oxidation takes place on the electrode surface with fouling effect, which does not affect a wide linear working range between 1 μM and 100 μM. Sensitivities, at pH 5 and pH 7, are calculated to be 0.11 μA μM−1 and 0.10 μA μM−1, respectively. The detection limits were determined to be 0.036 μM and 0.024 μM for pH 5 and pH 7, respectively. In the presence of uric acid, folic acid, ascorbic acid, and glucose no interference was noticed. This electrode showed remarkable stability and excellent reproducibility. The electrode was exploited for the determination of cysteine in a dietary supplement with the excellent recoveries. View Full-Text
Keywords: cysteine; determination; silver-copper sulfides; amperometry; electrochemical; impedance spectroscopy; FTIR; electroanalysis cysteine; determination; silver-copper sulfides; amperometry; electrochemical; impedance spectroscopy; FTIR; electroanalysis
Show Figures

Figure 1

MDPI and ACS Style

Vladislavić, N.; Rončević, I.Š.; Buljac, M.; Brinić, S.; Krivić, D.; Buzuk, M. Electroanalytical Determination of Cysteine Using the Electrodes Based on Ternary Silver-Copper Sulfides. Sensors 2018, 18, 3753.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop