Identification of phoxim and omethoate using α-hemolysin nanopore and aptamers.

Contamination with pesticides has inflicted substantial harm on human health; therefore, developing rapid, ultra-sensitive, and non-labelling simultaneous detection methods for multiple pesticides is necessary. In this study, we demonstrated that α-hemolysin (α-HL) nanopore sensor can detect and discriminate organophosphorus pesticides of phoxim and omethoate in a single nanopore without requiring labels of the probes or purification of the pesticides in real samples. Aptamers specifically recognise and bind pesticides to obtain pesticide-aptamer complexes that produce characteristic current signals while passing through the nanopore. Phoxim and omethoate were accurately distinguished by a portable instrument within minutes, and their detection sensitivity was up to the femtomole level, whether detected alone or simultaneously. The detection limits of phoxim and omethoate were 8.13 × 10−16 M and 4.16 × 10−15 M. The recoveries of phoxim and omethoate from pear, tomato, and cucumber samples were 82.0–107.0 % and 81.9–118.3 % respectively, with coefficient of variable below 8.0 %. • The α-hemolysin nanopore sensor can detect and discriminate phoxim and omethoate in real samples. • The sensor enables simultaneously detection of phoxim and omethoate within minutes. • The detection limit of the sensor is up to the femtomole level. • The sensor is as reliable and accurate as UHPLC-MS/MS. [ABSTRACT FROM AUTHOR]