School of Materials Science and Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea.
Department of Chemistry, Medi-Caps University, Indore 453331, Madhya Pradesh, India.
Biosensors (Basel). 2023 Nov 2;13(11):967. doi: 10.3390/bios13110967.
L-tryptophan (L-TRP) is an essential amino acid responsible for the establishment and maintenance of a positive nitrogen equilibrium in the nutrition of human beings. Therefore, it is vital to quantify the amount of L-tryptophan in our body. Herein, we report the MoS/S@g-CN-modified glassy carbon electrode for the electrochemical detection of L-tryptophan (L-TRP). The MoS/S@g-CN composite was successfully synthesized using an efficient and cost-effective hydrothermal method. The physical and chemical properties of the synthesized composite were analyzed using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray analysis (EDX). The crystallite size of the composite was calculated as 39.4 nm, with porous balls of MoS decorated over the S@g-CN surface. The XPS spectrum confirmed the presence of Mo, S, O, C, and N elements in the sample. The synthesized nanocomposite was further used to modify the glassy carbon (GC) electrode (MoS/S@g-CN/GC). This MoS/S@g-CN/GC was used for the electrochemical detection of L-TRP using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. For the purpose of comparison, the effects of the scanning rate and the concentration of L-TRP on the current response for the bare GC, S@g-CN/GC, MoS/GC, and MoS/S@g-CN/GC were studied in detail. The MoS/S@g-CN-modified GC electrode exhibited a rational limit of detection (LoD) of 0.03 µM and a sensitivity of 1.74 µA/ µMcm, with excellent stability, efficient repeatability, and high selectivity for L-TRP detection.
L-色氨酸（L-TRP）是一种必需氨基酸，负责人类营养中的正氮平衡的建立和维持。因此，定量我们体内的 L-色氨酸含量至关重要。在此，我们报告了 MoS/S@g-CN 修饰玻碳电极用于电化学检测 L-色氨酸（L-TRP）。MoS/S@g-CN 复合材料是通过高效且经济有效的水热法成功合成的。使用粉末 X 射线衍射（PXRD）、扫描电子显微镜（SEM）、X 射线光电子能谱（XPS）和能量色散 X 射线分析（EDX）分析了合成复合材料的物理和化学性质。该复合材料的晶粒尺寸计算为 39.4nm，多孔 MoS 球装饰在 S@g-CN 表面上。XPS 光谱证实了样品中存在 Mo、S、O、C 和 N 元素。进一步将合成的纳米复合材料用于修饰玻碳（GC）电极（MoS/S@g-CN/GC）。使用循环伏安法（CV）和差分脉冲伏安法（DPV）技术，通过 MoS/S@g-CN/GC 对 L-TRP 进行了电化学检测。为了进行比较，详细研究了裸 GC、S@g-CN/GC、MoS/GC 和 MoS/S@g-CN/GC 的扫描速率和 L-TRP 浓度对电流响应的影响。MoS/S@g-CN 修饰的 GC 电极表现出合理的检测限（LoD）为 0.03µM 和灵敏度为 1.74µA/µMcm，具有出色的稳定性、高效的重复性和对 L-TRP 检测的高选择性。
