Quantification of proteins by functionalized gold nanoparticles using click chemistry.

This letter presents a click-chemistry-based assay for proteins (CAP) that allows quantitative determination of the concentration of proteins, using azide- and alkyne-functionalized gold nanoparticles (AuNPs). Compared with conventional methods, CAP has a broader linear range for detection of proteins with good selectivity. CAP enables the analysis of total proteins in various sera and milk samples.