An Ultrasensitive Plasmonic Nanosensor for Aldehydes.

Glucose is the most common but important aldehyde, and it is necessary to create biosensors with high sensitivity and anti-interference to detect it. Under the existence of silver ions and aldehyde compounds, single gold nanoparticles and freshly formed silver atoms could respectively act as core and shell, which finally form a core-shell structure. By observing the reaction between glucose and Tollens' reagent, metallic silver was found to be reduced on the surface of gold nanoparticles and formed Au@Ag nanoparticles that lead to a direct wavelength shift. Based on this principle and combined with in situ plasmon resonance scattering spectra, a plasmonic nanosensor was successfully applied in identifying aldehyde compounds with excellent sensitivity and specificity. This ultrasensitive sensor was successfully further utilized to detect blood glucose in mice serum samples, exhibiting good anti-interference ability and great promise for future clinical application.