Catalysis of Gold Nanoparticles within Lysozyme Single Crystals

Hidden treasure: Gold nanoparticles (AuNPs) within a single protein crystal of lysozyme (see scheme, pink) are shown to efficiently catalyze the reduction of p-nitrophenol by NaBH4, and the catalytic activity initially increased with increased size of AuNPs until the size reached 7.4 nm, after which the activity decreased with increasing size of the AuNPs. The use of chemicals to either accelerate or inhibit the activity is also demonstrated.