Lei Zhen, Guo Jingfang, Zou Jing, Wang Zhenxin
School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan, 430205, People's Republic of China.
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, People's Republic of China.
Mikrochim Acta. 2022 Sep 5;189(10):369. doi: 10.1007/s00604-022-05472-6.
Ag nanoparticle-decorated TiC nanosheets (AgNPs@TiC NSs) were facilely synthesized via a self-reduction approach, in which TiC NSs acted as both reductant and supporter. The AgNPs@TiC NS nanocomposite exhibited excellent peroxidase-like activity with o-phenylenediamine (OPD) and HO as substrates. The catalytic behavior followed the typical Michaelis-Menten kinetics; Michaelis constant (K) and maximum initial velocity (V) for OPD were 0.263 mM and 43.2 × 10 M s, indicating high affinity and high catalytic efficiency towards OPD. The catalytic mechanism was revealed to be an accelerated electron transfer process. Based on the inhibition effect on the peroxidase-like activity of AgNPs@TiC NSs, a simple, fast, and sensitive colorimetric method for detection of low-weight biothiols (cysteine (Cys), homocysteine (Hcy), and glutathione (GSH)) was developed by measuring the absorbance at 425 nm. The colorimetric method displayed wide linear range (50 nM to 50 μM for Cys, 10 nM to 250 μM for Hcy, 10 nM to 50 μM for GSH), low limit of detection (48.5 nM for Cys, 5.5 nM for Hcy, 7.0 nM for GSH), and good selectivity and short assay time (3 min). Moreover, the feasibility of this colorimetric sensor was demonstrated by accurately determining Cys in diluted human serum samples; good recovery (95.9-101.0%) and low relative standard deviations (2.8-4.9%) were obtained, showing great promise for point-of-care test in clinical samples.
通过自还原法轻松合成了银纳米颗粒修饰的碳化钛纳米片（AgNPs@TiC NSs），其中TiC NSs既作为还原剂又作为载体。AgNPs@TiC NS纳米复合材料以邻苯二胺（OPD）和HO为底物表现出优异的过氧化物酶样活性。催化行为遵循典型的米氏动力学；OPD的米氏常数（K）和最大初始速度（V）分别为0.263 mM和43.2×10 M s，表明对OPD具有高亲和力和高催化效率。催化机制被揭示为加速电子转移过程。基于对AgNPs@TiC NSs过氧化物酶样活性的抑制作用，通过测量425 nm处的吸光度，开发了一种简单、快速且灵敏的比色法用于检测低分子量生物硫醇（半胱氨酸（Cys）、同型半胱氨酸（Hcy）和谷胱甘肽（GSH））。该比色法显示出宽线性范围（Cys为50 nM至50 μM，Hcy为10 nM至250 μM，GSH为10 nM至50 μM）、低检测限（Cys为48.5 nM，Hcy为5.5 nM，GSH为7.0 nM）以及良好的选择性和短测定时间（3分钟）。此外，通过准确测定稀释人血清样品中的Cys证明了该比色传感器的可行性；获得了良好的回收率（95.9 - 101.0%）和低相对标准偏差（2.8 - 4.9%），显示出在临床样品即时检测中具有巨大潜力。
