Silk Derived Fe/N-Doping Porous Carbon Nanosheets for Chloramphenicol Electrochemical Detection

Abstract

Background: The use of modified electrochemical sensors is essential for the detection of antibiotic drug abuse. The main objective of this article is to develop a silk-derived carbon material for the modification of pyrolytic graphite electrodes (PGE) for the sensitive detection of chloramphenicol (CAP). Methods: We proposed a pyrolysis synthesis of porous carbon nanosheets (Fe-Silk PNC) using silk as a precursor. Properties of carbon nanosheets had been improved by the Fe-Nx atoms doping, which was attributed to the β-sheet structures and amino-group-rich chemical structures of silk fibroin, and this material has been used to modify the pyrolytic graphite electrode (PGE) for the electrochemical determination of CAP. Scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR) were used to determine the morphology and properties of Fe-Silk PNC surface. In the electrochemical determination, cyclic voltammetry (CV) showed a superior current response while bare electrode performed an inferior result. In addition, different scan rate, pH, accumulation time and accumulation potential were carefully optimized, which proved that this material is appropriate for CAP detection. Finally, differential pulse voltammetry (DPV) method was used for quantitative measurements. Result: In this study, DPV determination of CAP showed the linear relationship with increasing concentration ranged from 1 to 200 μM, and the low detection limit was 0.57 μM (S/N = 3). SEM and FT-IR results further demonstrated the N-doped carbon nanomaterials were successfully synthesized. With excellent sensing performance achieved, the practicability of the sensor has been evaluated to detect CAP in chicken, shrimps and fish. Conclusion: In summary, a silk derived biomass porous carbon nanomaterial Fe-Silk PNC was simply fabricated and used as a novel electrode material. This kind of novel Fe-Silk PNC modified electrode exhibited excellent sensitivity, anti-interference ability, repeatability, wide linear rang, and was successfully used for determination of CAP in real samples. Therefore, the biomass derived nanomaterial is expected to be used in new sensing materials.