Cascade nanozymatic network mimicking cells with selective and linear perception of HO

• Published in: Chemical science (Cambridge) 2023-06, Vol.14 (24), p.678-6791
• Main Authors: Zhu, Caixia, Zhou, Zhixin, Gao, Xuejiao J, Tao, Yanhong, Cao, Xuwen, Xu, Yuan, Shen, Yanfei, Liu, Songqin, Zhang, Yuanjian
• Format: Article
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d3sc01714a

A single stimulus leading to multiple responses is an essential function of many biological networks, which enable complex life activities. However, it is challenging to duplicate a similar chemical reaction network (CRN) using non-living chemicals, aiming at the disclosure of the origin of life. Herein, we report a nanozyme-based CRN with feedback and feedforward functions for the first time. It demonstrates multiple responses at different modes and intensities upon a single H 2 O 2 stimulus. In the two-electron cascade oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB), the endogenous product H 2 O 2 competitively inhibited substrates in the first one-electron oxidation reaction on a single-atom nanozyme (Co-N-CNTs) and strikingly accelerated the second one-electron oxidation reaction under a micellar nanozyme. As a proof-of-concept, we further confined the nanozymatic network to a microfluidic chip as a simplified artificial cell. It exhibited remarkable selectivity and linearity in the perception of H 2 O 2 stimulus against more than 20 interferences in a wide range of concentrations (0.01-100 mM) and offered an instructive platform for studying primordial life-like processes. A cascade network is built using nanozymes, reminiscent of hypotheses of nonbiological matters as the origin of evolution. It shows selective recognition against 20+ interferences and linear perception of H 2 O 2 of different concentrations.