Glassy Carbon Electrode Modified with Silver Nanodendrites Implemented in Polylactide‐Thiacalix[4]arene Copolymer for the Electrochemical Determination of Tryptophan

Abstract

Glassy carbon electrode (GCE) was modified by new polymeric materials obtained from oligolactides by cross‐linking with tetracarboxylated thiacalix[4]arene in cone, partial cone and 1,3‐alternate configurations and then silver was deposited by potential cycling in the pores of the polymer film. The modified electrode showed highly sensitive and selective signal toward tryptophan which was irreversibly oxidized on the coating due to Ag+ assisted accumulation in the surface layer. The role of macrocycle configuration and conditions for Ag nanodendrites formation are described. Granulation of the polymer films caused by the macrocycles improves both the conditions for silver deposition and tryptophan determination. The electrochemical sensor developed makes it possible to determine from 0.1 to 100 μM of tryptophan with the limit of detection down to 0.03 μM. No interference with oxidation of other amino acids (phenylalanine, histidine, cysteine and tyrosine) was found. The electrochemical sensor developed was validated in the determination of tryptophan sedative medication “Formula of calmness” in the presence of vitamins B5 and B6.

Facile Preparation of Fe3O4/C Nanocomposite and Its Application for Cost-Effective and Sensitive Detection of Tryptophan

“…At present, various analytical techniques have been developed for the identification and determination of Trp, including but not limited to high-performance liquid chromatography [4], capillary electrophoresis [5], spectrofluorimetry [6], colorimetric method [7], chemiluminescence [8], and electroanalytical methods [3,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24]. Compared with other techniques, electroanalytical methods are very suitable for the determination of biomolecules due to their considerable advantages, such as rapid response, facile operation, high sensitivity, and easy miniaturization.…”

“…Compared with other techniques, electroanalytical methods are very suitable for the determination of biomolecules due to their considerable advantages, such as rapid response, facile operation, high sensitivity, and easy miniaturization. Moreover, Trp has desirable electrochemical activity, which is favorable for electrochemical determination [9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24]. However, it is difficult to directly detect Trp on bare electrodes, owing to the high overpotential resulting from the sluggish electrode kinetics [3].…”

“…Various modified electrodes have been successfully applied to detect Trp in actual samples [3,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24]. Nevertheless, they still suffer from some draws, including complexity [3,21,22,23], low detection limit (LOD), narrow linear range [9,10,11,12,13,14,15,16,21,23,24], and the high cost of precious metal nanoparticles [3,17,18,19,20], which severely hinder their widespread practice applications. Therefore, the development of novel low-cost, but highly efficient, modification materials for sensing Trp is utmost critical and remains a great challenge.…”

The Role of Calix[n]arenes and Pillar[n]arenes in the Design of Silver Nanoparticles: Self-Assembly and Application

“…Silver dendrites deposited on films offer detection of cholinesterase substrate. These nanomaterials were used in electrochemical sensors, allowing to detect 0.1 to 100 µM of tryptophan with the limit of detection down to 0.03 µM [100]. No interference with oxidation of other amino acids (phenylalanine, histidine, cysteine and tyrosine) was found.…”

Carbon-paste nanocomposites as unconventional gate electrodes for electrolyte-gated organic field-effect transistors: electrical modulation and bio-sensing

“…2D illustrates excellent sensitivity, reproducibility and regression line (r 2 = 0.9996), achieving promising analytical results by means of detection limits at picomolar levels (1.0 AE 0.1 pM) as well as a wide range of linear response from 10 À12 to 10 À9 M. Interestingly, while common carbon-based electrochemical sensing devices determine TRP in the nM range, the present approach based on a carbon-based EGOFET platform is capable of achieving the detection of pM concentrations, demonstrating the high sensitivity of the transistor. [36][37][38] It is also important to point out the renewability of the bio-recognition system by a simple polishing step without losing sensibility. As it is depicted in Fig.…”