Construction of a non-enzymatic electrochemical sensor based on graphitic carbon nitride nanosheets for sensitive detection of procalcitonin

In this study, we established a label free and ultrasensitive electrochemical sensor based on graphitic nitride nanosheets (g-C(3)N(4) NS) for procalcitonin (PCT) detection. Firstly, an easy-to-prepare and well-conducting g-C(3)N(4) NS was synthesized. Next the g-C(3)N(4) NS was immobilized on the electrode surface by π–π stacking, and further used to anchor the specific recognition peptide (PP). The surface morphology and structure after g-C(3)N(4) NS and PP modification was characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and electrochemistry. The sensing property of this sensor was evaluated by differential pulse voltammetry (DPV) and showed a detection sensitivity with a dynamic range from 0.15 to 11.7 fg mL(−1) with a low limit of detection (LOD) of 0.11 fg mL(−1). Besides, the electrochemical biosensor was successfully used to detect PCT in human serum samples, and the results suggest its potential use in clinical application.