Figure 5.

(a) Advancing from single−biomarker sensing to multiplex sensing. Diagnostic screening of patient−derived biopsies with multiplex sensors demonstrates high sensitivity and specificity in comparison of single sensors. (b) Principles of multiplexed detection using the surface−enhanced Raman scattering (SERS) technique, with metal nanoparticles that are different in size and shape and have unique Raman signals with narrow peaks, thus, they could be used as SERS tags. In addition, schematic illustration of simultaneous detection of COVID−19-associated antigen expressed by SERS imaging.