Silver nanoparticle decorated graphene-based SERS electrode towards procalcitonin detection

Abstract

Monitoring procalcitonin levels (PCT) is critical for early diagnosis of sepsis, chronic disease, COVID-19 and other time-dependent pathologic cases. In this work, silver nanoparticles (AgNps) doped graphene-based Surface-enhanced Raman scattering (SERS) electrode was demonstrated for the first time to rapid detection of PCT biomarkers. An excellent combination of AgNps and single-layer graphene (SLG) was achieved, resulting in effective SERS enhancement. Due to the smooth and large surface area of SLG, many antibody molecules bind to the surface of SERS electrode and interact with PCT protein. The SERS enhancement factors (EFs) for R6G and PCT protein molecules were calculated to be 1012 and 1.6 × 109, respectively. The limits of detection (LODs) for R6G and PCT protein molecules were reported to be 10−13 M and 4 ngmL−1, respectively. These high EFs and lower LODs indicate that the fabricated AgNp/Gr@ ITO SERS electrodes have perfect SERS performance. SERS studies showed that there is a perfect interaction between PCT protein and AgNps and SLG, which leads to the enhancement of electromagnetic mechanism (EM) and chemical mechanism (CM) in the fabricated SERS materials. The developed eco-friendly SERS platform can provide reliable and sensitive test results, faster analysis compared to conventional biosensors, mobile applications and cost-effective clinical management.