Monodispersed Au nanoparticles decorated MoS2 nanosheets with enhanced peroxidase-like activity based electrochemical H2O2 sensing for anticancer drug evaluations
Qiwen Liu, Yang Huang, Sheng Wang, Shuo Yang, Zhengjin Jiang, Shengfeng Huang
Abstract
Background The unique size, physical and chemical properties, and ultra-high stability of nanozymes have attracted extensive attentions in sensing, but improvement of catalytic activity of the nanozymes is still an urgent issue. Given the ultra-high simulated enzyme activity of metal nanoparticles and the advantage of multi-enzyme catalysis, an Au-decorated MoS 2 nanosheets (MoS 2 /Au NS) integrating the double peroxidase-like (POD) activity is developed. Results By optimizing and adjusting the density of AuNPs , as well as its morphology and other parameters, a monodisperse and high-density distribution of AuNPs on MoS 2 nanosheets was obtained, which can greatly improve the POD-like activity of MoS 2 /Au NS. Nafion solution was applied to assist the modification of MoS 2 /Au NS on the electrode surface so as to improved its stability. An electrochemical H 2 O 2 detection platform was constructed by modifying MoS 2 /Au NS nanozyme on the SPCE using the conductive Nafion solution. And the negatively charged sulfonic acid group can eliminate negatively charged electroactive substances to improve the specificity. Then ascorbic acid was used to stimulate tumor cells to produce H 2 O 2 as therapeutic model, an ultrasensitive chronocoulometry detection for H 2 O 2 in cell lysate was established. The logarithmically of ΔQ and the logarithmically of H 2 O 2 concentration showed a good linear relationship between 1 μM and 500 mM, with a LOD value of 0.3 μM. Significance The developed H 2 O 2 sensor has excellent stability, reproducibility (RSD = 2.3 %, n = 6) and selectivity, realized the quantitative detection of H 2 O 2 in cell lysate. Compared with commercial fluorescence detection kits for H 2 O 2 in cell lysate, it is worth mentioning that the electrochemical H 2 O 2 sensor developed in this study is simpler and faster, with higher sensitivity and lower cost. This provides a potential substitute for disease diagnosis and treatment evaluation based on accurate detection of H 2 O 2 .