Determination of Copper(II) by Anodic Stripping Voltammetry at a 2,5-Dimercapto-1,3,4-thiadiazol Self-assembled Monolayer-based Gold Electrode

Abstract

2,5-Dimercapto-1,3,4-thiadiazol (DMTD) can bind on the surface of a gold electrode through the strong gold-sulfur interaction. The fabrication and electrochemical characteristics of the DMTD self-assembled monolayer (SAM)-modified gold electrode were investigated. The DMTD SAM electrode exhibited a significantly increased sensitivity. Cu(II) was accumulated in phosphate buffer (pH 4.6) at a potential of -0.6 V (vs. Ag/AgCl) for 40 s and then determined by anodic stripping voltammetry (ASV) in copper-free phosphate buffer (pH 5.0). The effects of various parameters, such as the pH values of the preconcentration solution and measurement solution, the accumulation potential, and the accumulation time, were investigated. Under the optimum conditions, a linear calibration graph was obtained in the concentration range of 8.0 × 10 -6 to 8.0 × 10 -5 mol l -1 with a correlation coefficient of 0.9978. The relative standard deviations for eight successive determinations were 4.3 and 2.9% for 1.0 × 10 -5 and 2.0 × 10 -5 mol l -1 Cu(II), respectively. The detection limit (three times signal to noise) was 4.0 × 10 -7 mol l -1 . The proposed voltammetric method was utilized successfully to detect the concentration of Cu(II) ions in tap water samples.

Do copper ions activate tyrosinase enzyme? A biosensor model for the solution

“…The detection limit of the biosensor was calculated to be 0.95 μM by using 3S b /m criteria, where m is the slope of the calibration curve and S b is the standard deviation of the responses (n = 10) from 2.5 μM Cu 2+ . Table 1 shows a comparison of analytical parameters such as the linear range and detection limit of some sensors and biosensors developed for copper assay [27,28] and [32][33][34][35][36][37][38][39][40]. The biosensor offers attractive properties compared to some of previous studies such as high sensitivity, a wide linear range (2.5 μM-20.0 μM), and low detection limit (0.95 μM).…”

Electrocatalytic Oxidation and Determination of Morin at a Poly(2,5-dimercapto-1,3,4-thiadiazole) Modified Carbon Fiber Paper Electrode

“…43 Gold electrodes modified with self-assembled monolayer of DMTD was reported for the electrochemical determination of Pb(II) or Cu(II). 44,45 Electrodes modified by DMTD have also been applied in the electrochemical analysis of several biological samples. 46,47 The present work focuses on electrochemical behavior of morin on carbon fiber paper (CFP) electrode modified by electropolymerization of DMTD.…”

Formation, Characterization, and Applications of Organic and Inorganic Nanometric Films

“…This approach has been used by us and others as a means of assembling selective voltammetric electrodes. [12][13][14][15][16][17][18][19][20][21][22][23][24][25] For example, Turyan and Mandler accomplished the selective extraction and determination of Cr(VI) was accomplished using a 4-mercaptoethylpyridinium monolayer [26] on Au. Pyridinium groups are known to form strong complexes with chromates and were the driving force for the high selectivity that was found.…”