An easy fabricated biomimetic leaf microreactor for photocatalytic nicotinamide adenine dinucleotide (NADH) regeneration

Nicotinamide adenine dinucleotide (NADH) is an essential coenzyme for many oxidoreductases in enzyme-catalyzed reactions. However, the reuse of NADH is necessary owing to its high price and high consumption. By mimicking the photosynthesis and leaf structure of plants, we designed a biomimetic leaf microreactor consisting of glass and waterproof double-sided tape for artificial photosynthesis. The glass substrates of the microreactor mimic the cuticle of the leaf epidermal cells to avoid water evaporation. In addition, the high flexibility of the waterproof double-sided tape makes it possible to prepare microreactors rapidly, without the constraints of expensive molds and materials. Moreover, the waterproof double-sided tape makes it easy and fast to combine the microchamber with the glass substrates without plasma bonding. The regeneration ratio of NADH in the biomimetic leaf microreactor reached 87.19%. To further increase the throughput, we propose a concept of a “leaf mosaic” microreactor array based on the leaf mosaic structure of plants. • The glass matrix of the microreactor mimics the cuticle of leaf epidermal cells, avoiding the effect of water evaporation. • The high flexibility of the double-sided tape makes it possible to prepare microreactors quickly, free from the constraints of expensive molds and materials. • The combination of the microchamber with the glass substrates easy and fast, without plasma bonding. • The biomimetic leaf microreactor exhibits excellent photocatalytic capacity for highly efficient NADH regeneration and L-glutamate synthesis.