Electrochemical Sensitive Determination of Sepsis Biomarker Procalcitonin at Graphitic Carbon Nitride Nanosheets Modified Electrodes

Abstract

A label-free and ultrasensitive electrochemical biosensor based on the specific recognition peptide and ultrathin graphitic carbon nitride nanosheets (g-C3N4 NS) was successfully fabricated to detect the procalcitonin (ProCT), a new biomarker for sepsis diagnosis. The introduction of g-C3N4 NS to modify the glassy carbon electrode, due to the higher surface potential and exposure of more active sites, demonstrated ultra-sensitive sensing performance. The surface morphology and structure after g-C3N4 NS modified was characterization by XPS, AFM and electrochemistry. The sensing property of this sensor was evaluated by differential pulse voltammetry and showed a detection sensitivity with the dynamic range from 0.15 to 11.7 fg/mL and the low detection limit (LOD) of 0.11fg/mL. Besides, the electrochemical biosensor was also successfully applied to detect ProCT in human serum sample.