A new enzymatic approach for the fabrication of gold nanoparticles (Au NPs) decorated with a functional protein was developed using a recombinant glycerol dehydrogenase from Bacillus stearothermophilus (BsGLD) that was tagged with an N-terminal protein G domain and a C-terminal (His)₆Cys tag. The recombinant BsGLD promoted the synthesis of the Au NPs via the catalytic reduction of nicotinamide adenine dinucleotide using glycerol as a substrate, and the recombinant BsGLD was self-immobilized on the Au NPs as a result of the protein G's binding capability for IgG antibody.