Current techniques for plasmonic immunoassay often require the introduction and additional conjugation of enzyme, and thus cannot accommodate conventional immunoassay platforms. Herein, we develop a plasmonic nanosensor that well accommodates conventional immunoassays and dramatically improves their sensitivity and stability. This plasmonic nanosensor directly employs alkaline phosphatase-triggered click chemistry between azide/alkyne functionalized gold nanoparticles as the readout. This straightforward approach broadens the applicability of nanoparticle-based immunoassays and has great potential for applications in resource-constrained settings.
Keywords: alkaline phosphatase; click chemistry; gold nanoparticles; naked-eye readout; plasmonic immunoassay.