Generation of gold nanostructures at the surface of platinum electrode by electrodeposition for ECL detection for CE

Abstract

In this paper, we report a sensitive method for ECL detection for CE based on generation of gold nanostructures at the surface of Pt electrode by electrodeposition. Difenidol hydrochloride was used as a model analyte. With the increase of electrodeposition amount, the morphology of gold nanostructures changed from discrete nanoflowers to dense nanoparticle array. Interestingly, the variation of deposition amount also greatly affected the ECL intensity of difenidol. The ECL intensity increased remarkably with deposition amount and reached the maximum value at the deposition amount of 7.0 Â 10 À8 C; further increasing the deposition amount, however, caused the ECL intensity to decrease. Other conditions, including applied potential, injection time and voltage, buffer pH, were also optimized in detail. Under the optimized conditions, the linear response range of difenidol is from 1.0 Â 10 À8 to 5.0 Â 10 À5 M, and the detection limit was 4.0 Â 10 À9 M (S/N 5 3). The RSDs of ECL intensity and migration time were 2.0 and 1.6%, respectively (n 5 5, at 7.5 mM difenidol). Compared with using bare electrode, the detection sensitivity was significantly improved by ca. two orders of magnitude. Notably, the nanogold was prepared at the surface of electrode and no nanogold was added to the electrophoretic buffer or detection cell, thus causing no interference to the separation. Finally, the proposed method was successfully applied to the analysis of difenidol in tablets and urine samples. With high sensitivity and good reproducibility, this method provides a promising platform for the determination of pharmaceuticals that have a tertiary amine group such as difenidol. 3 -based ECL detection offers lower background noise, higher detection sensitivity and has been adopted widely for detection of various analytes [4][5][6][7][8][9]. Coupling ECL detection with CE has also been widely investigated, and a variety of methods have been developed to enhance the sensitivity of ECL detection [10][11][12]. KeywordsMetal nanoparticles have attracted much interest in analytical chemistry because of their easy preparation and relatively large surface area, size-controllability and unusual chemical properties [13][14][15]. Specifically, Pt and Au nanoparticles (Pt/AuNPs) have shown some fascinating properties in modifying electrode [16][17][18][19]. They can increase the electrode surface area, promote electron transfer and thus enhance the detection sensitivity [20,21]

Formation of 3-Dimensional Gold, Copper and Palladium Microelectrode Arrays for Enhanced Electrochemical Sensing Applications

“…For the deposition of Au (Figure 3a), a single reduction feature is present, beginning at ~0.5 V, consistent with previous studies [18,19], and is attributed to the reduction of AuCl 4 − (aq) to metallic gold: false[AuCl4false]−+3e−→ Au+4Cl−…”

On‐line preconcentration strategy for the simultaneous quantification of three local anesthetics in human urine using CZE

“…Several methods employing CE are described for the simultaneous determination of some drugs of abuse in urine, hair, and blood, including PRO, LID, or BUP . The simultaneous determination of PRO, LID, and BUP has been previously carried out by CE but with electrochemiluminescence (ECL) detection and using SDS and Tween‐20 mixed micelles to improve the resolution.…”

“…In the present work, FASI has been successfully applied as in previous works where biological specimens, such a human urine, hair, and blood were analyzed for different drugs .…”

A novel electrochemiluminescence sensor for the determination of diphenidol based on a nano-TiO2/silica sol/PVP/Ru(bpy)32+ modified gold electrode

“…1 At present, there are many methods for the detection of diphenidol, including (reverse phase) high performance liquid chromatography (RP-HPLC, HPLC), [2][3][4][5] microfluidic chip, 6 anionic surfactant titration, 7 non-aqueous titration, 8 postchemiluminescence 9 and electrochemiluminescence (ECL). [10][11][12] In these methods, chromatography possesses high accuracy, good repeatability and wide application, but the equipment required is expensive, and the chemiluminescence method has high sensitivity, good selectivity and rapid analysis; however, the application of chemiluminescence is limited because of poor stability. In the same manner, non-aqueous titration has the shortcomings of large error and complex operation.…”

“…In contrast, electrochemiluminescence techniques have been applied widely in the detection and analysis of drugs for its advantages of high sensitivity, wide linear range, rapid analysis speed, simple instrument and convenient operation. According to existing methods of capillary electrophoresis-electrochemiluminescence (CE-ECL) and electrochemiluminescence (ECL) for the determination of diphenidol, the types of working electrodes include a bare electrode and modified electrodes such as Pt disk working electrode, 10 Pt electrode modified with gold nanostructures 11 and glassy carbon electrode with ruthenium(II) tris(bipyridine)/ multiwalled carbon nanotubes/Nafion composite film. 12 However, the use of nano-TiO 2 /silica sol/PVP/Ru(bpy) 3 2+ as a modified electrode material to prepare a novel high-performance sensor has not been reported to date.…”