Simultaneous Detection of Six Different Types of Pesticides by an Immunosensor Based on Surface Plasmon Resonance

Six pesticides, azoxystrobin, boscalid, chlorfenapyr, imazalil, isoxathion, and nitenpyram, were simultaneously detected by using a surface plasmon resonance (SPR) immunosensor. 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.