Selective Detection of Methomyl Pesticide by a Catalytic Chemosensing Assay

Abstract

The catalytic chemosensing assay (CCA), an ew indicatord isplacement assay,w as developed for selectived etection of methomyl,ahighlyt oxic pesticide. Trimetallic complex {[Fe II (dmbpy)(CN) 4 ]-[Pt II (DMSO)Cl] 2-[Ru II (bpy) 2 (CN) 2 ]} (1;d mbpy = 4,4'-dimethyl-2,2'-bipyridine, bpy = 2,2'-bipyridine) was synthesized as at ask-specific catalyst to initially reduce and degrade methomyl to CH 3 SH/CH 3 NH 2 /CH 3 CN/ CO 2 .T he thus-produced CH 3 SH interactsw ith the trimetallic complex to displace the cis-[Ru II (bpy) 2 (CN) 2 ]l uminophore for monitoring. Other pesticides, including organophosphates and similar carbamate pesticides, remained intact under the same catalytic conditions;aselectives ensings ignal is only activated when 1 recognizes methomyl. Furthermore, 1 can be applied to detect methomyl in real waters amples.I nt he luminescent mode of the assay,t he method detection limit (MDL)o f1 for methomyl (LD 50 = 17 mg kg À1)w as 1.12 mg L À1 .