Enantioselective discrimination of
chiral molecules is essential
in chemistry, biology, and medical science due to the configuration-dependent
activities of enantiomers. Therefore, identifying a specific amino
acid and distinguishing it from its enantiomer by using nanomaterials
with outstanding performance are of great significance. Herein, blue-
and green-emitting chiral silicon nanoparticles named bSiNPs and gSiNPs,
respectively, with excellent water solubility, salt resistance, pH
stability, photobleaching resistance, biocompatibility, and ability
to promote soybean germination, were fabricated in a facile one-step
method. Especially, chiral gSiNPs presented excellent fluorescence
recognition ability for glutamic acid enantiomers within 1 min, and
the enantiomeric recognition difference factor was as high as 9.0.
The mechanism for enantiomeric fluorescence recognition was systematically
explored by combining the fluorescence spectra with density functional
theory (DFT) calculation. Presumably, the different Gibbs free energy
and hydrogen-bonding interaction of the chiral recognition module
with glutamic acid enantiomers mainly contributed to the difference
in the fluorescence signals. Most noteworthy was the fact that the
chiral gSiNPs can showcase not only the ability to recognize l- and d-glutamic acids in living cells but also the test
strips fabricated by soaking gSiNPs can be applied for d-glutamic
acid visual detection. As a result, this study provided insights into
the design of multifunctional chiral sensing nanoplatforms for enantiomeric
detection and other applications.