Recent advances on the development of plasmon-assisted biosensors for detection of C-reactive protein

Human C-reactive protein (CRP), an early clinical indicator of infectious or inflammatory conditions has been recently identified as a key biomarker associated with the development of COVID-19. The rapid and accurate determination of CRP level in blood serum is an urgent need to predict timely the risk of disease worsening. The emergence of nanotechnological tools has provided an attractive perspective in designing portable bioanalytical assays with fast response time, high sensitivity and specificity, and multiplexing capability for accurate, on-site disease diagnosis and monitoring. Due to their versatile optical properties, plasmonic nanoparticles (PNPs) are appealing candidates for biosensing applications. This review summarizes the advances in the application of PNPs for CRP detection and quantification. Particularly, we review the improvements attained in the detection of CRP using aggregation-based colorimetric, localized surface plasmon resonance (LSPR), plasmon-assisted fluorescence and chemiluminescence, and surface-enhanced Raman scattering (SERS) spectroscopic methods.