Simultaneous detection of six different types of pesticides by an immunosensor based on surface plasmon resonance

Abstract

Six pesticides, azoxystrobin, boscalid, chlorfenapyr. imazalil. isoxathion, and nitenpyram. were simultaneously detected by using a surface plasmon resonance (SPR) imnumosensor. The working ranges were 3.5-19 ng/mL for azoxystrobin. 4.5-50 ng/mL for boscalid. 2.5-25 ng/mL for chlorfenapyr, 5.5-50 ng/mL for imazalil. 3.5-50 ng/mL for isoxathion. and 8.5-110 ng/mL for nitenpyram. They showed adequate recovery results in tomato samples: 104-116% for azoxystrobin. 94-101% for boscalid. 90-112% for chlorfenapyr. 96-106% for imazalil. 107-119% for isoxathion. and 104-109% for nitenpyram. The correlation coefficient with liquid chromatography (HPLC or LC-MS/MS) using vegetable samples also agreed well: 0.91-0.99 as R2 without strong bias, except for nitenpyram for which the SPR immunosensor sensitivity was too low. The SPR immunosensor will have high applicability for pesticide residue analyses in vegetable samples.