Graphene Quantum Dot-Based SEPSIS Immunosensor Using Procalcitonin as a Biomarker

Abstract

This study presents a targeted impedimetric immunosensor for the detection of procalcitonin (PCT), a biomarker associated with SEPSIS. The immunosensor was operated based on the interaction between PCT antibody (anti-PCT) and PCT antigen, utilizing graphene quantum dot (GQD)-modified carbon screen-printed electrode (SPCE). Herein, GQDs, known for their large surface area and excellent electrical conductivity, served as the matrix for immobilizing anti-PCT, thereby enhancing the electrochemical signal. Following the immobilization of anti-PCT onto the GQD@SPCE, the interaction between anti-PCT and with PCT antigen was monitored by using electrochemical impedance spectroscopy. Experimental parameters were optimized, and the analytical characteristics were extensively evaluated. The developed impedimetric PCT immunosensor demonstrated a linear detection range of 0.1–10 ng/mL for PCT, with a detection limit of 0.01 ng/mL and a quantification limit of 0.03 ng/mL. Finally, developed GQD-based impedimetric PCT immunosensor was applied to low- and high-level original control serum samples of the selected kit and very promising recovery values were obtained.