A polyoxometalate based electrochemical sensor for efficient detection of L-cysteine

Abstract

L-cysteine (L-cys), as an important sulfur-containing amino acid, plays an indispensable role in biological systems. Too low and excessively high ratio of L-cys will cause harm to the function of human organs. Therefore, it is very necessary to develop efficient methods to detect it in multifarious samples. This paper has built an electrochemical sensor by combining Keggin-type polyoxometalate (PMo 9 V 3 ) and cobalt tetrasulfonate (II) phthalocyanine (CoTsPc) on indium tin oxide electrodes using the layer-level self-assembly technology for efficiently detection of L-cys. The assembly process and surface morphology of the modified electrode was characterized by ultraviolet-visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscope, and atomic force microscopy. The conditions of electro-catalysed oxidation of L-cys were optimized by cyclic voltammetry, and the kinetic electrochemical parameters were also evaluated by electrochemical impedance spectra. Furthermore, the sensing performance of the modified electrode was explored using amperometry. The proposed electrochemical L-cys sensor was found to have superior sensing performance with a range of linear response of 2.5 × 10 -7 to 1.7 × 10 -4 mol•L −1 and 1.7 × 10 −4 to 39.5 × 10 −4 mol•L −1 , the detection limit of 1.0 × 10 -7 mol•L −1 (signal/ noise = 3), and satisfactory anti-interference ability. Consequently, the fabricated sensor has the potential to be applied in laboratory practices for L-cys deterimination in commercial drinks.

Ultrathin Cu–TCPP Nanosheet-Based Electrochemical Microsensor for Detecting the Immunosuppressive Drug Mycophenolic Acid

“…As shown in the Nyquist plots of different Cu–TCPP MOFs and blank electrode (Figure S5), the visible semicircles are observed for all the measured spectra while they display different shapes. The semicircle part in the high-frequency region of Nyquist plot is related to charge-transfer resistance ( R ct ) . As can be seen from the plots, 2D Cu–TCPP nanosheets show the smallest semicircle, indicating fast charge transfer.…”

“…The semicircle part in the high-frequency region of Nyquist plot is related to chargetransfer resistance (R ct ). 41 As can be seen from the plots, 2D Cu−TCPP nanosheets show the smallest semicircle, indicating fast charge transfer. We also tested the specific surface area and electrochemically active surface area (EASA) of both 2D and bulk Cu−TCPP MOFs.…”

Highly Efficient Photocatalysts: Polyoxometalate Synthons Enable Tailored CdS–MoS2 Morphologies and Enhanced H2 Evolution

“…Polyoxometalates (POMs) possess various desirable properties, including stable structure, tunable size and anionic charge, controllable solubility in both organic and aqueous solvents, catalytic capability, electrical conductivity, luminescence, magnetism, antiviral properties, reversible redox activity, and semiconductor-like properties. − Most importantly, it can serve as a preassembled platform with multiple pretransition-metal sources and a fixed ratio of bimetallic sources under hydrothermal conditions. − …”

In situcoupling of a Co–Mo bimetallic sulfide derived from [CoMo12O40]6−clusters showing highly efficient electrocatalytic hydrogen evolution

“…With the increasing demand for energy, [1][2][3] renewable energy has been [4][5][6][7] explored and utilized, [8][9][10][11][12][13][14] and electrochemical water cracking [15][16][17] is a promising and effective way to solve the energy and environmental crises. 18 It is critical to find lowcost, earth-abundant catalysts instead of noble-metals or noble-metallic oxides such as Pt, IrO 2 and RuO 2 .…”