Electrochemistry of chloramphenicol on laser-induced graphene electrodes and its voltammetric determination in honey

Abstract

Laser scribing is a promising technology for the rapid and large-scale production of low-cost electrochemical sensors from diverse substrates. Polyimide has been the most popular so far because of its low cost, flexibility and capability of generating high-quality porous graphene films, known as laser-induced graphene (LIG). Herein we report the electrochemistry of chloramphenicol (CAP) on LIG electrodes and its determination in honey samples. LIG electrodes were fabricated by the photothermal conversion of sp³ carbon within the polymeric matrix into sp² carbon using a CO₂ laser cutter. The LIG electrode associated with differential pulse voltammetry (DPV) showed good linearity (R² > 0.99) in the range from 10 to 160 μmol L⁻¹ with a limit of detection of 1.0 μmol L⁻¹ and good precision (RSD < 5%) for the electrochemical reduction of CAP species. Detection was possible free from the interference of other antibiotics, such as amoxicillin, tetracycline, sulfanilamide, and sulfamethoxazole. Spiked honey samples were analyzed by the standard-addition method and recovery values between 86 and 109% were obtained, which confirmed the absence of sample matrix effects. Therefore, the proposed sensor is an alternative, feasible, low-cost, and powerful analytical tool for the determination of CAP in honey.