A chiral silicon-based electrochemical sensor for the detection of L-glutamate

Abstract

L-Glutamate (L-Glu), a major excitatory neurotransmitter in the central nervous system, plays an important role in nitrogen metabolism. In this study, chiral mesoporous imprinted silica nanoparticles (CMISNs) were synthesized via the sol-gel method using L-Glu derivatives as templates. Subsequently, the AuNPs/CMISNs@CMK-3/GCE electrochemical sensing interface was constructed. Benefiting from the chiral mesoporous structure of CMISNs and combined high conductivity of CMK-3 and signal amplification effect of gold nanoparticles (AuNPs), the designed electrochemical sensor enables specific detection of L-Glu. The developed sensor exhibits a wide linear response range for L-Glu (1 nM to 1 mM), with a limit of detection of 0.15 nM and a limit of quantification of 0.52 nM. It also demonstrated remarkable enantioselectivity, achieving a chiral separation factor of 7.7 toward glutamate enantiomers, along with good reproducibility (RSD = 3.2%, n = 5). The sensor retained excellent stability over 14 days and high selectivity against potential interferents. In contrast to conventional enzyme-based biosensors, chiral recognition is achieved by imprinted mesopores of L-Glu without the involvement of biological enzymes. This work provides a novel bionic sensing platform for the precise detection of L-Glu, which holds significant potential in neuroscience research and clinical diagnosis.

Graphical abstract