Raman Enhancement-Nanozyme Dual Functional Nanocomposite Au@MnO2-based Surface Enhanced Raman Scattering Biosensor for Organophosphorus Pesticides
10.19756/j.issn.0253-3820.251225
- VernacularTitle:具有拉曼增强-纳米酶双功能的Au@MnO2纳米复合材料用于有机磷农药的表面增强拉曼散射生物传感
- Author:
Xiao-Tong ZHANG
1
;
Meng-Ren XUAN
;
Fu-Gang XU
;
Yue ZHANG
Author Information
1. 江西师范大学化学与材料学院,南昌 330022
- Keywords:
Manganese dioxide;
Organophosphorous pesticide;
Nanozyme;
Surface enhanced Raman scattering;
Biosensor
- From:
Chinese Journal of Analytical Chemistry
2025;53(10):1664-1673,中插1-中插4
- CountryChina
- Language:Chinese
-
Abstract:
Surface enhanced Raman scattering(SERS)is an important technique for detecting pesticide residues.However,many pesticides have small Raman scattering cross sections and low affinity for gold/silver enhancement substrates,resulting in low sensitivity for direct SERS detection.Indirect methods typically require complex surface modifications and have poor universality.Here,a dual functional composite Au@MnO2 combined with acetylcholinesterase(AChE)was proposed for SERS biosensing of pesticides.The Au@MnO2 with oxidase-like activity could oxidize 3,3′,5,5′-tetramethylbenzidine(TMB)into oxTMB with a large Raman scattering cross section,producing strong SERS signal using Au@MnO2 itself as enhancement substrate.In the presence of AChE,acetylthiocholine(ATCh)was catalytically hydrolyzed to produce thiocholine(TCh),and its reducibility could induce the decomposition of MnO2.Consequently,oxidase-like activity of Au@MnO2 was declined,less oxTMB was produced,and gold nanoparticles(AuNPs)detached from the MnO2 layer,resulting in a weakened SERS response.Organophosphorus pesticides(OPs),as inhibitors of AChE,prevented the production of TCh,thereby blocking the decomposition of MnO2 and leading to the recovery of Raman signals.Under optimized conditions,the Raman signal switching strategy was successfully used for detection of three OPs,i.e.,fenthion,chlorpyrifos,and methyl parathion,with detection limits of 4×10-11 mol/L,2×10-9 mol/L,and 3×10-9 mol/L,respectively.In actual spinach sample testing,the spiked recoveries of the three OPs ranged from 86.5%to 110.6%.This study provided a new strategy for detecting pesticide residues using SERS.
