Stimulus-Responsive Catalytic Nanosystems Based on DNA-Encoded Copper Nanoclusters and the DNA Allosteric Effect

DNA-encoded nanomaterials have been widely developed, of which the properties are dependent on the DNA sequences and structures. Herein, stimulus-responsive catalytic nanosystems are presented based on DNA-templated copper nanoclusters (DNA-CuNCs) and the DNA allosteric effect. DNA-CuNCs synthesized with one of the DNA homopolymers, poly guanine with 5 guanine bases (5G DNA), as the template reveal apparent and stable catalytic activity toward 4-nitrophenol reduction by NaBH₄. The rules are disclosed regarding the inhibition effects of diverse DNA on the catalytic activity of 5G-CuNCs. Of note, through adjusting the molar ratio of poly adenine (polyA) and poly thymine (polyT) from 1:1 to 1:2, a triplex DNA structure consisting of T-A·T triplets (poly(TAT)) was generated from a duplex with T-A base pairings (poly(AT)), which enabled the catalytic activity of 5G-CuNCs restored from the inactivated states in the presence of polyA or poly(AT). Hence, catalytic properties of 5G-CuNCs are encoded by different DNA structures and regulated reversibly through fuel-driven DNA allostery between duplex poly(AT) and triplex poly(TAT), thus yielding intriguing switchable catalytic nanosystems, which are also utilized for sensing designated DNA strands or one early cancer biomarker. It is believed that our research will contribute to formulating smart nanoprobes and nanodrugs for precise detection and therapy in the future.