Plasmonic sensing of β-glucuronidase activity via silver mirror reaction on gold nanostars

We outline a novel approach for the plasmonic detection of β-glucuronidase activity by modulating the silver mirror reaction at the nanoscale on gold nanostars. β-glucuronidase catalyzes the hydrolysis of a non-reducing substrate to generate reducing products that trigger the silver mirror reaction on gold nanostars to alter their surface plasmon resonance. By modulating the silver deposition on gold nanostars, the unique plasmonic property of silver-coated gold nanostars enables a significant change in the surface plasmon resonance that allows for a plasmonic readout for detecting the enzymatic activity. This plasmonic nanosensor enables a detection of the β-glucuronidase activity as low as 0.1 U/L, showing great promise as a plasmonic approach for enzyme detection.