Alkanethiols Modified Gold Electrodes for Selective Detection of Molecules with Different Polarity and Molecular Size. Application to Vitamin B2 Analysis

Abstract

The cyclic voltammetry behavior of several molecules with different polarity and molecular size on gold electrodes modified with nonfunctionalized alkanethiols of different chain length, usually employed as chromatographic stationary phases, are studied. The redox systems hexacyanoferrate(II/III), ferrocene/ferrocine and hydroquinone/ quinone are chosen as template molecules. As modifiers, ethanethiol, 1-octanethiol and di-n-octadecyldisulfide are selected. We can conclude that polar molecules can reach the electrode surface through channels created by the modifiers. However, when nonpolar compounds are analyzed, the nonpolar interactions between the analyte and the terminal group of the modifier lead to retention of the compound, retarding its arrival to the electrode surface. A molecule with polar and nonpolar part was used for the application of this conclusion. If the gold electrode is modified with di-n-octadecyldisulfide, the electrochemical behavior of vitamin B2 becomes simpler than that observed on a bare one. This result allows a sensitive and selective procedure to be developed for direct determination of vitamin B2 in pharmaceutical formulations.

Atomic Force Microscopy Study of new Sensing Platforms: Cucurbit[n]uril (n=6, 7) on Gold

“…The oxidation of gold and later reduction of gold oxides by means of cyclic voltammetric scans up to 1.5 V (vs. Ag/AgCl/3 M KCl) were used to estimate the electrochemical active surface of gold electrodes modified with alkanethiols [19]. The oxidation of gold and later reduction of gold oxides by means of cyclic voltammetric scans up to 1.5 V (vs. Ag/AgCl/3 M KCl) were used to estimate the electrochemical active surface of gold electrodes modified with alkanethiols [19].…”

Recent Advances in Electroanalysis of Vitamins

“…Gold electrodes modified with alkanethiols and homoadenine single‐stranded DNA/molybdenum disulfide‐graphene nanocomposite were also proposed for the analysis of pharmaceutical and urine samples, respectively. Figure reports the fabrication process of the rMoS 2 ‐graphene/A 32 /Au electrode and its application for riboflavin sensing.…”

Binary Metal Oxide Adsorbed Graphene Modified Glassy Carbon Electrode for Detection of Riboflavin

“…These studies indicate that the nature of electrode material plays a vital role in achieving the required detection sensitivity and linear range of a given analyte. Chromium doped SnO 2 [16] and nickel doped CeO 2 [17], MnO 2 [18], Manganese (III) Tetraphenylporphyrin [19], ZnO [20], (WO 3 , SnO 2 ) modified carbon paste, and ionic liquid [21], Co 2 + -Y zeolite CPE [22], Bismuth [23], 3-amino-5-mercapto-1, 2, 4-triazole [24], metallosilicate [25] and alkane thiol modified gold electrode [26] were previously reported and these modified electrodes showed higher catalytic activities than the unmodified electrodes [27]. Recently, whole cell-based electrochemical sensors were developed with riboflavin and cytochrome c in which electroactive bacteria was employed as biocatalyst and the sensor exhibits good sensitivity [28,29].…”