Electrochemical recognition for D and L-Cysteine using an achiral monodisperse Cu catalyst restricted by nanosized SOD zeolite cage domain

Abstract

The recognition for D and L-Cysteine (Cys) broke through to 0.008 pM by the electrochemistry catalyst Cu Sodalite (SOD) zeolite without enzymes or noble metals. The SOD structured zeolite supplied nanosized SOD cages which are highly consistent with the spatial configuration of cysteine. And the applied electric field magnified the subtle differences in binding energy between D and L-Cys through the highly active Cu catalyst. Under electrochemical aspects, these results manifest themselves as distinguishable current peaks and potential intervals. Unlike the related literature, the sharp and sensitive current peak created by Cu catalyst is set as baseline with the absence of cysteine. With the continually increasing concentration of D or L-Cys, L-Cys shifts to the positive potential, and D-Cys shifts to the negative potential. The result reveals good reproducibility and high specificity that the catalyst is insensitive to other amino acids. The novel catalyst is featured by low cost and high stability, besides higher activity than enzymes.