Gold Nanorod-Mediated Photothermal Enhancement of the Biocatalytic Activity of a Polymer-Encapsulated Enzyme

The rational integration of biomolecules and functional nanostructures can enable remote-controlled biological processes such as molecular transport, catalysis, and molecular recognition. The photothermal ability of plasmonic nanostructures is highly attractive for optically modulating biomolecular processes such as biocatalysis. However, the studies pertaining to the photothermal enhancement of enzyme activity are mostly limited to thermophilic enzymes because of the thermal denaturation and loss of the activity of conventional enzymes at elevated temperatures. The lack of effective strategies for preserving the activity of immobilized enzymes at elevated temperatures hinders the potential use of plasmonic nanostructures as nanoheaters for the photothermal enhancement of enzyme activity. Here, we demonstrate a simple and highly effective strategy for stabilizing enzymes immobilized on plasmonic nanostructures by encapsulating them through <i>in situ</i> polymerization. Apart from enhanced thermal and biological stability, the encapsulation strategy provides enhancement of enzyme activity with an external optical trigger. The encapsulation strategy demonstrated here can be a highly attractive approach for designing remote-controlled biomolecular reactions.