Metal and Metal Oxide Nanoparticles to Enhance the Performance of Enzyme-Linked Immunosorbent Assay (ELISA)

Enzyme-linked immunosorbent assay (ELISA) is a technique designed for the detection and quantification of (bio)molecules in a liquid sample. It is a powerful tool in clinical diagnostics, food safety, and environmental monitoring. However, the main limitation of conventional ELISA is its low sensitivity, which cannot meet the demand of analyte analysis in complex (biological) samples. Several successful approaches capitalizing on the unique physical and chemical properties of nanoparticles to improve the performance of traditional ELISA have been reported. In this review, we aim to demonstrate diverse strategies designed to date that use metal and metal oxide nanoparticles to overcome challenges associated with ELISA sensitivity and stability. In particular, we discuss metal and metal oxide nanoparticles as carriers to load enzymes and antibodies for signal amplification, as enzyme mimics to replace the natural enzyme label, and as signal transducers to provide fluorescence or luminescence signals as an alternative output.