A New approach for simultaneous detection and photocatalytic degradation of imidacloprid and dinotefuran in water using terbium-based fluorometry and mixed-phase TiO2.

Abstract

This study explores a novel method for detecting neonicotinoid insecticides, imidacloprid (IMD) and dinotefuran (DNT), in water using terbium (Tb³⁺) ions photo probe. The optimal excitation and emission wavelengths for Tb³⁺ luminescence were identified at 310 nm and 545 nm, respectively. The influence of pH and solvent on Tb-complex fluorescence was investigated. Results indicate a significant enhancement of luminescence intensity at pH 6 for IMD in DMF and pH 7.0 for DNT in DMSO. The fluorescence intensity exhibited a linear relationship with IMD and DNT concentrations ranging from 0.1 to 20 µg/mL (R² > 0.99). Limits of quantitation (LOQ) were determined as 0.1 µg/mL for IMD and 0.05 µg/mL for DNT. This newly developed photo probe demonstrates the potential for monitoring photolysis and photocatalytic degradation of these neonicotinoids using TiO₂ as a catalyst under controlled photoreactor conditions. The method offers a promising alternative for rapidly and sensitively detecting these prevalent insecticides in water samples.