The Selective Detection of Cyantraniliprole Insecticides Using Molecularly Imprinted Polymers Coupled with an Acetylcholinesterase Inhibition-Based Biosensor.

Cyantraniliprole is one of the anthranilic diamide insecticides widely used in the agriculture sector. Due to its low toxicity and relatively fast degradation, there is need for a sensitive determination method for its residues. Nowadays, there is growing interest in the development of enzyme-based biosensors. The major drawback is the non-specific binding of many insecticides to the enzyme. This work employs Molecularly imprinted polymers (MIPs) to increase enzyme specificity and eliminate the organic solvent effect on the enzyme activity. The synthesized Cyan-Molecularly imprinted polymers (Cyan-MIP) possesses high affinity and selectivity toward cyantraniliprole. Acetylcholinesterase assay characteristics including enzyme concentration, substrate concentration, DTNB concentration, and acetonitrile concentration were optimized. Under optimal experimental conditions, the developed MIP-Acetylcholinesterase (MIP-AchE) inhibition-based sensor provides better precision than the AchE inhibition-based sensor with a wide linear range (15-50 ppm), limit of detection (LOD) 4.1 ppm, and limit of quantitation (LOQ) 12.6 ppm. The sensor was successfully applied for cyantraniliprole determination in spiked melon, giving satisfactory recoveries.

Benzimidazole-triazole ligands with pendent triazole functionality: unexpected formation and effects on copper-catalyzed aerobic alcohol oxidation.

A series of benzimidazole-triazole ligands (NN') having a pendent triazole arm with different triazole substituents including CH2Ph (3a), cyclo-C6H11 (3b), and CH2SiMe3 (3c) were obtained in moderate yields from Cu-catalyzed oxidative C-N cyclization of the respective amine-triazole compounds N,N'-bis((1-R-1,2,3-triazol-4-yl)methyl)benzene-1,2-diamine (2a-2c). Treatment of CuCl2 with one equiv. of the benzimidazole-triazole ligands afforded the corresponding CuII complexes with the empirical formula of Cu(NN')Cl2 (4a-4c). Crystal structures of 4b and 4c reveal mononuclear and dinuclear CuII complexes, respectively. Despite the differences in triazole substituents and their solid state structures, ESR spectra indicate the same molecular structures in CH3CN solution whereas CV data suggest similar redox potentials for 4a-4c. Catalytic activities for aerobic oxidation of benzyl alcohol to benzaldehyde follow this trend: 4c > 4a > 4b. In addition, the catalytic system 4c/TEMPO/Cu0/NMI (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyloxyl, NMI = N-methylimidazole) exhibited high activities for oxidation of activated alcohols (i.e., benzyl alcohol derivatives and allylic alcohol) in CH3CN at room temperature.