Efficient NAD⁺ regeneration facilitated by synergistically intensified charge generation and transfer in fullerene/porphyrin assemblies

Enzymatic catalysis exhibits the merits of high catalytic rates and specificity, whereas a major obstacle that hampers commercialization is the need for expensive nicotinamide adenine dinucleotide (NAD(+)) cofactor; thus the regeneration of NAD(+) is necessary. Here, we report a fullerene-based photocatalyst (C-60-ZnTPP) capable of regenerating NAD(+) through oxidation of NADH by photogenerated holes, accompanied by simultaneous hydrogen formation. Zinc meso-tetraphenylporphine (ZnTPP) and C-60 are combined as a donor-acceptor (D-A) structure with a robust internal electric field (IEF, 5.67 times greater than that of ZnTPP), ensuring ultrafast (similar to 1 ps) and long-lived charge separation (>3 ns) and transfer, which is conducive to improving the performance of photocatalytic regeneration of NAD(+). NADH is used as the sole hole sacrificial agent in the system, achieving up to 98.6% NAD(+) regeneration within 5 h under visible light (>= 420 nm) illumination. Equivalent oxidation of ethanol is catalyzed by alcohol dehydrogenase, a key enzyme in human alcohol metabolism, to verify the enzymatic activity of photocatalyzed NAD(+). This work provides an extended choice of materials available for photocatalytic NAD(+) regeneration, offering valuable insights into optimizing efficient cofactor regeneration pathways.