Pt nanoparticle/N-doped graphene nanozymes for colorimetric detection of acetylcholinesterase activity and inhibition

Herein, Pt nanoparticles encapsulated in two-dimensioanl (2D) N-doped graphene (Pt/NG) nanozymes containing abundant active Pt sites is rationally fabricated by a one-pot pyrolysis of EDTA-Pt complex. The 2D sheet structure and the reconstructed electronic structures enable Pt/NG nanozymes exhibiting excellent peroxidase-mimicking activity. Taking advantages of the remarkable catalytic activity of Pt/NG nanozymes, a colorimetric assay is strategically constructed for sensitively determining acetylcholinesterase (AChE) activity and tacrine based on the thiocholine-regulated effect towards the peroxidase-like activity of Pt/NG. The detection limit for AChE activity can achieve as low as 0.0652 mU mL−1, and the half maximal inhibitory concentration (IC50) value of tacrine for AChE is about 0.954 µM. The robust analytical performance in serum samples test verifies the great application potential of this assay in real matrix. Furthermore, "IMPLICATION-AND" logic gate is constructed based on the proposed colorimetric assay. This work not only provides one sustainable and effective avenue to fabricate Pt-based peroxidase mimic with high catalytic performance, but also gives new impetuses for developing novel colorimetric assay by applying Pt-based enzyme mimics as substitutes for the natural enzymes.