Multicolor enzyme-linked immunosorbent sensor for sensitive detection of organophosphorus pesticides based on TMB2+-mediated etching of gold nanorods

Abstract A multicolor enzyme-linked immunosorbent sensor was constructed to detect organophosphates pesticides (OPs) on base of TMB2+-mediated AuNRs etching. As the etching progresses, a rainbow-like color responses was generated. The naked eye limit of detection (LOD) of the sensing system is 0.25 ng mL-1. In particular, the longitudinal localized surface plasmon resonances (LSPR) peak shift of AuNRs is linearly correlated with the logarithm of OPs concentration in range of 104 to 5×106 pg mL-1 for parathion-methyl and fenitrothion, 5×104 to 107 pg mL-1 for fenthion, respectively. Compared with reported methods, this sensor displayed satisfactory linear ranges and detection limits. Average recoveries of this method ranged from 73.28% to 98.08% and relative standard deviations (RSDs) were below 8.0% as for food samples analysis without complicated pretreatments. Remarkably, the developed multicolor enzyme-linked immunosorbent sensor is capable of providing accurate and reliable assay for OPs in complex food samples.