Chirality, as an intrinsic feature of the living world, is associated with many significant biological processes. Although the chiral-induced spin selectivity (CISS) effects have been recognized and applied to provide spin control over chemical reactions, their implementation in the organic electrochemical transistor (OECT) remains a largely unexplored area. Herein, the OECT technology is combined with a photovoltaic gate electrode and the CISS effect, establishing a chiral organic photoelectrochemical transistor (OPECT) for enantiomer identification. The chiral Sn(II)-based metal-organic framework (SnMOF)/SnO2 hybrid, serving as a spin filter to induce CISS properties, is coated on a TiO2 nanotube array-based photosensitive gate. Using cystine enantiomers as proof-of-principle, a target recognition-induced electron donor (l-/d-cysteine) generation was further proposed. The CISS effect enables a more efficient transfer of spin-polarized electrons between the L-target and L-gate (or between the D-target and D-gate), inducing a greater channel current (ID) variation. The comprehensive analysis of the ID responses in the two chiral OPECT sensors further enables accurate and reliable determination of the concentration and composition of enantiomers in unknown mixtures. This study provides a straightforward methodology to apply the CISS effect for determining chiral targets in complex samples.
Keywords: enantioselectvity; nanoconfinement effect; organic photoelectrochemical transistors; organic/inorganic hybrid; spin selectivity effect.