Hump-shaped seven-core fiber-based WaveFlex biosensor for rapid detection of glyphosate pesticides in real food samples

Abstract

At present, pesticides are widely used in the cultivation of crops. Glyphosate is widely used in many pesticides. Glyphosate ingestion can cause a series of health problems. Therefore, this paper proposes to use localized surface plasmon resonance (LSPR) technology to develop a WaveFlex biosensor (plasma wave-based optical fiber sensor) to detect glyphosate concentration in pesticides. The evanescent field is improved by using the fusion of seven-core fiber and single-mode fiber and the tapering of the sensing area to improve the sensing performance. The gold nanoparticles (AuNPs) are used to excite the LSPR effect. Multi-walled carbon nanotubes (MWCNTs) and cerium oxide nanorods (CeO2-NRs) are used to increase the surface area and promote the adhesion of the enzyme. The sensitivity of the sensor is 137.7 pm/µM in the range of 0-60 µM glyphosate concentration, and the limit of detection (LoD) is 1.94 µM, which has good performance in compared to the existing biosensors. Subsequently, the sensor was tested for reusability, reproducibility, selectivity, stability, and excellent results were obtained. Finally, the sensor is tested on real samples, and the results show that it can be applied in practical applications. The test findings demonstrate that the sensor has a great deal of potential for use in glyphosate content detection in food samples.