Contact Electrification–Based Enantioselective Recognition of Chiral Amino Acids through Stereospecific Interfacial Electron Transfer

Chirality lies at the heart of chemistry, governing the structure-function relationships of biomolecules, pharmaceuticals, and catalysts. However, rapid and label-free enantioselective analysis remains an enduring challenge due to the intrinsic similarity of enantiomers' physicochemical properties. Here, we report a contact electrification-based triboelectric sensing platform for the enantioselective recognition of chiral amino acids, achieved by coating CuO nanowires. The approach exploits chirality-dependent interfacial electron transfer, whereby differences in molecular orbital alignment and work function between enantiomers generate distinct electronic signatures during controlled contact-separation with acetone. Kelvin probe force microscopy, ultraviolet photoelectron spectroscopy, and density functional theory calculations reveal that subtle differences in side-chain geometry modulate nanoscale surface potentials and electron cloud overlap, leading to quantifiable shifts in charge transfer efficiency. The method achieves millisecond-scale discrimination across charged, polar uncharged, and sulfur-containing amino acids, with orthogonal evidence from molecule specific enantioselective contact-electrocatalytic degradation of methyl orange. By transducing stereochemical information directly into measurable electrical outputs, this work demonstrates a mechanistically grounded chemical sensing paradigm, offering a versatile platform for pharmaceutical quality control and biomolecular diagnostics.