Highly sensitive homogeneous-heterogeneous nanogold-based microimmunoassays for multi-residue screening of pesticides in drinking water

A homogeneous-heterogeneous immunoassay based on the use of antibody modified gold nanoparticles, 5 and 50 nm in diameter, is developed with without signal amplification. The assays involve capture target analytes homogeneous phase subsequent detection immunoreaction product, following a heterogeneous scheme performed regular DVD. analytical approach was evaluated developing multiplexed competitive immunoassays for determination residues pesticides chlorpyrifos azoxystrobin as model targets. results revealed that immunocapture strategy improves considerably assay performance, giving better sensitivity when compared to standard format. Under best conditions, least detectable level were 0.1 μg/L. also highly selective, showing little or no cross-reactivity other structurally similar compounds. assessed by analysis water. reference chromatographic methods, recovery agreed. good recoveries obtained (mean values ranging between 80% 125%) make this suitable screening biosensing methodology either environmental monitoring laboratory quantification pesticide sample treatment maximum time 65 min at lower cost. • Reliable concept. Effective water pollution microimmunoassays compact versatile disk. novel comply requirements framework directives.