Electrochemical Aptasensor for L-Histidine Detection via Self-Cleavage of DNAzymes and Amplification of End-Truncated Elongated Tetrahexaheral Gold Nanocrystals

Abstract

A sensitive aptamer-based signal-on sensor for real-time detection of L-histidine via self-cleavage of DNAzymes and amplification of elongated tetrahexaheral gold nanocrystals (end-truncated-ETHH-Au-NCs) is presented. The introduction of target L-histidine induced self-cleavage of DNAzymes on the end-truncated-ETHH-Au-NCs modified glassy carbon electrode (GCE) into the solution. The resulting change in electron transfer efficiency is readily measured by square wave voltammetry (SWV) at target L-histidine concentrations as low as 0.1 pM, the increase in the SWV peak current is linear with the concentration of L-histidine in the range from 0.1 pM to 0.1 μM. The fabricated aptasensor shows a high specificity for L-histidine which is not affected by the coexistence of other amino acids, and an excellent enantio-selectivity toward L-histidine was achieved.