(Invited) Disposable Polyurethane Nanospiked Gold Electrode-Based Label-Free Electrochemical Immunosensor for Clostridium Difficile

摘要

A polyurethane (PU) nanospiked gold electrode-based label-free electrochemical immunosensor for Clostridium difficile (C. difficile) toxin B detection was developed. Different from nanomaterials-modified electrode, the PU nanospiked gold electrode was fricated by soft lithography directly. The morphology of the nanospiked electrode was characterized by scanning electron microscope (SEM), and its good electrochemical performance was demonstrated by cyclic voltammetry (CV) as well as differential pulse voltammetry (DPV). Then, the PU nanospiked gold electrode-based immunosensor was developed by fixing anti-toxin B single domain antibody on the electrode surface as the receptor. DPV was used as a detection technology for C. difficile toxin B detection. It revealed that the immunosensor has good specificity, repeatability, and stability. Even in a label-free style, the limit of detection for toxin B was 0.5 pg/mL. With the increase of the concentration of toxin B from 1 pg/mL to 130 pg/mL, a linear relationship was observed between the peak current and toxin concentration. Compared with flat PU electrode-based immunosensor, the detection signal of PU nanospiked gold electrode-based immunosensor was amplified about 6 times. Benefitted from its low cost and simple processing, the PU nanospiked gold electrode-based immunosensor can be used a disposable electrochemical sensor for toxin B rapid detection.