Peroxidase-like activity of Ru–N–C nanozymes in colorimetric assay of acetylcholinesterase activity

Herein, the Ru-N-C nanozymes with abundant active Ru-Nx sites have been successfully prepared by pyrolyzing Ru(acac)3 trapped zeolitic-imidazolate-frameworks (Ru(acac)3@ZIF-8). Taking advantages of the remarkable peroxidase-mimicking activity, outstanding stability and reusability of Ru-N-C nanozymes, a novel biosensing system with explicit mechanism is strategically fabricated for sensitively determining acetylcholinesterase (AChE) and tacrine. The limit of detection for AChE activity can achieve as low as 0.0433 mU mL-1, and the IC50 value of tacrine for AChE is about 0.190 μmol L-1. The robust analytical performance in serums test verifies the great application potential of this assay in real matrix. Furthermore, "INH" and "IMPLICATION-AND" logic gates are rationally constructed based on the proposed colorimetric sensor. This work not only provides one sustainable and effective avenue to fabricate Ru-N-C-based peroxidase mimic with high catalytic performance, and also gives new impetuses for developing novel biosensors by applying Ru-N-C-based enzyme mimics as substitutes for the natural enzyme.