L-histidine-regulated zeolitic imidazolate framework modified electrochemical interface for enantioselective determination of L-glutamate

Metal-organic framework (MOF)-based electrochemical interface presents a broad platform for the chiral recognition of amino acids, but the inferior conductivity of most MOFs limits the sensitivity in practical applications of electrochemical sensing. Therefore, the L-histidine-regulated zeolitic imidazolate framework (L-His-ZIF) was proposed as a novel electrochemical interface for simple, efficient, and enantioselective determination of L-glutamate (L-Glu) based on the electrochemical impedance spectroscopy (EIS). Based on the resistance change, the L-His-ZIF interface can be directly used for chiral recognition without the assistance of high-conductive substances, where multiple immobilizations are generally required in MOF-involved voltammetry. The stacked L-His-ZIF nano-polyhedrons provided numerous cavities and high specific surface area, thereby forming adequate chiral recognition sites. Based on the L-His-ZIF interface, the enantioselective detection of L-Glu-was successfully achieved with a good linear relationship with the impedance difference in the range from 0.1 nM to 50 nM with the detection limit of 0.06 nM. This prepared ZIF-functionalized electrode provided the desired enantioselectivity and reproducibility with robust chiral recognition in the real application. More importantly, MOF-modified EIS can be applied for more chiral recognition of enantiomers by various MOF interfaces, which has great potential for applications in pharmaceutical monitoring and biochemical analysis. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The L-His-ZIF interface showed excellent chiral recognition performance for enantiomeric detection of L-Glu, providing desired enantioselectivity and reproducibility in real applications. The MOF-modified EIS interface can be used for more chiral recognition of enantiomers, with great potential for applications in pharmaceutical monitoring and biochemical analysis.