Precise Tuning of the D-Band Center of Dual-Atomic Enzymes for Catalytic Therapy.

Single-atom nanozyme-based catalytic therapy is of great interest in the field of tumor catalytic therapy; however, their development suffers from the low affinity of nanozymes to the substrates (H 2 O 2 or O 2 ), leading to deficient catalytic activity in the tumor microenvironment. Herein, we report a new strategy for precisely tuning the d-band center of dual-atomic sites to enhance the affinity of metal atomic sites and substrates on a class of edge-rich N-doped porous carbon dual-atomic sites Fe-Mn (Fe 1 Mn 1 -NC e ) for greatly boosting multiple-enzyme-like catalytic activities. The as-made Fe 1 Mn 1 -NC e achieved a much higher catalytic efficiency ( K cat / K m = 4.01 × 10 5 S -1 ·M -1 ) than Fe 1 -NC e ( K cat / K m = 2.41 × 10 4 S -1 ·M -1 ) with an outstanding stability of over 90% activity retention after 1 year, which is the best among the reported dual-atom nanozymes. Theoretical calculations reveal that the synergetic effect of Mn upshifts the d-band center of Fe from -1.113 to -0.564 eV and enhances the adsorption capacity for the substrate, thus accelerating the dissociation of H 2 O 2 and weakening the O-O bond on O 2 . We further demonstrated that the superior enzyme-like catalytic activity of Fe 1 Mn 1 -NC e combined with photothermal therapy could effectively inhibit tumor growth in vivo, with an inhibition rate of up to 95.74%, which is the highest value among the dual-atom artificial enzyme therapies reported so far.