Sensitive Voltammetric Sensor for Tryptophan Detection by Using Polyvinylpyrrolidone Functionalized Graphene/GCE

Abstract

In this paper, an electrochemical method for the measurement of tryptophan (Trp) was developed based on a glassy carbon electrode modified with polyvinylpyrrolidonefunctionalized graphene (PVP-GR)/glassy carbon electrode (GCE). In 0.1 M phosphate buffer solution (PBS, pH = 2.2), compared with bare GCE, PVP/GCE, and GR/GCE, the oxidation peak current of Trp increased dramatically at PVP-GR/GCE. The oxidation mechanism of Trp on the PVP-GR/GCE was discussed and the experimental conditions were optimized. Under the best experimental conditions, the oxidation peak current of Trp was proportional to its concentration in the range of 0.06 µM–10.0 µM and 10.0–100.0 µM, and the limit of detection (LOD) was 0.01 µM (S/N = 3). The target modified electrode with excellent repeatability, stability and selectivity, was successfully applied to detectTrp in drugs and biological samples.

Molecularly imprinted electrochemical aptasensor based on functionalized graphene and nitrogen-doped carbon quantum dots for trace cortisol assay

“…Graphene is a 2D carbon nanomaterial that shows the advantages of good electrical conductivity, large specific surface area and high mechanical strength. 24,25 However, when pure graphene is directly used as the electrode material, the utilization of specific surface area is easily reduced due to curling or stacking between layers, which further affects the conductivity of the electrode. Carbon quantum dots (CQDs) are small-size 0D carbon nanomaterials, which not only have low biotoxicity, good biocompatibility and stability 26,27 but also can effectively disperse graphene.…”

Highly Synergistic Sensor of Graphene Electrode Functionalized with Rutile TiO₂ Microstructures to Detect L-Tryptophan Compound

“…Electrochemical methods recently offer the advantages of simple instrumentation of amino acid analysis with low detection costs and rapid response. They have attracted a great deal of interest in the amino acid analysis 23,24) . Recently, voltammetry or amperometry methods are in great demand by researchers to identify Trp compounds.…”

Investigation of L-Tryptophan Electrochemical Oxidation with a Graphene-Modified Electrode

“…Among the methods used for the determination of tryptophan, chromatographic [ 17 ], chemiluminescence [ 18 ], capillary electrophoresis [ 19 ], and electrochemical techniques [ 20 ] were highly sensitive, accurate, and simple to use. Various materials for electrode modification have been employed so far, such as nitrogen-doped graphene nanosheets/CuCo 2 O 4 [ 21 ], poly(L-methionine)/graphene [ 22 ], a flower-like-structured nanocomposite consisting of reduced graphene oxide and SnO 2 [ 23 ], Cu 2 O-nanoparticle-coated reduced graphene oxide [ 24 ], polyvinylpyrrolidone-functionalized graphene [ 25 ], and 3D nitrogen and sulfur co-doped graphene/integrated polysaccharides [ 26 ]. To the best of our knowledge, no study has been published on tryptophan determination using nitrogen-, sulfur-, and boron-doped graphene.…”