Carbendazim is a broad-spectrum benzimidazole-type fungicide effective against fungi that compromise the safety/quality of food products. Despite its potential usefulness, carbendazim constitutes a major environmental pollutant, being hazardous for humans and animals; therefore, reliable determination of carbendazim levels in water, soil, and food samples remains a highly desirable analytical goal. Herein, an optical (white light reflectance spectroscopy, WLRS) label-free biosensor for fast and sensitive determination of carbendazim is presented. The transducer is a SiO2/Si chip, on which a suitable benzimidazole-conjugate has been immobilized; determination is based on the competitive immunoassay format: A mixture of an in-house developed anti-carbendazim antibody with the calibrators/samples is pumped over the chip, followed by biotinylated secondary antibody and unlabeled streptavidin. The WLRS platform allows for real-time monitoring of biomolecular interactions carried out onto the SiO2/Si chip by transforming the shift in the reflected interference spectrum caused by the immunoreaction to effective biomolecular adlayer thickness. The sensor is capable of detecting carbendazim levels within 28 min (LoD: 20 ng/mL; intra- and inter-assay CVs: ≤6.9% and ≤9.4%, respectively). Excellent analytical characteristics and short analysis time combined with its small size render the proposed WLRS biosensor ideal for future point-of-need determination of carbendazim in food and environmental samples.
Preparation of reduced graphene oxide decorated with Cu-Co Oxide Electrode and its application for Sensitive Determination of Nitrite in Food Samples
