Design of A Low-Cost and Disposable Paper-Based Immunosensor for the Rapid and Sensitive Detection of Aflatoxin B1

Chemosensors

DaniloM. dos Santos¹  DanielS. Correa¹  FernandaL. Migliorini¹  AndreyC. Soares¹  LuizH. C. Mattoso¹  OsvaldoN. Oliveira² 

[1] Nanotechnology National Laboratory for Agriculture, Embrapa Instrumentação, São Carlos 13560-970, SP, Brazil;São Carlos Institute of Physics, University of São Paulo, P.O. Box 369, São Carlos 13560-970, SP, Brazil;

关键词: disposable immunosensor;    electrochemical detection;    aflatoxin B1;    chitosan;    carbon nanotubes;    paper-based sensor;   

DOI  :  10.3390/chemosensors8030087

来源: DOAJ

【 摘 要 】

We report a paper-based electrochemical immunosensor made with sustainable materials to detect aflatoxin B1 (AFB1), a highly toxic, carcinogenic mycotoxin found in food. The immunosensor was prepared with a waterproof paper substrate and low-cost graphite-based conductive ink through a simple cut-printing method. The working electrode was functionalized with a drop-cast film of multiwalled carbon nanotubes (MWCNT)/chitosan on which a layer of anti-AFB1 monoclonal antibodies was immobilized covalently. The architecture of the immunosensor was confirmed with polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS) and electrochemical impedance spectroscopy (EIS), including the effective immobilization of the active layer of anti-AFB1. With EIS as the principle of detection, the immunosensor could detect AFB1 in the range from 1 to 30 ng·mL⁻¹, and detection limit of 0.62 ng·mL⁻¹. This sensitivity is sufficient to detect AFB1 in food according to regulatory agencies. The immunosensor exhibited good repeatability, reproducibility, stability, and selectivity in experiments with a possible interferent. Furthermore, detection of AFB1 in maize flour samples yielded recovery of 97–99%, in a demonstration of the possible use of the paper-based immunosensor to detect AFB1 using extraction solutions from food samples.

【 授权许可】

Unknown