Optical fiber probe based on LSPR for the detection of pesticide Thiram

This article introduces an innovative sensor designed to explore the localized surface plasmon resonance (LSPR) effect using optical fiber technology for the detection of pesticide Thiram. The proposed configuration consists of an etched silica multimode optical fiber coated with gold nanoparticle (AuNP) layers able to modulate the reflected signal. What sets this sensor apart is its ability to stimulate LSPR modes for single AuNPs, i.e. single layer, and aggregation states of nanoparticles or multilayer. This capability has been demonstrated through both numerical simulations and experimental results. Furthermore, the device has been applied to detect a specific pesticide, Thiram, serving as an illustrative example of chemical sensing, for concentrations within 0.1–100 μM, and achieving a low limit of detection (LOD) below 5 nM.