Sensitive Portable Electrochemical Sensors for Antibiotic Chloramphenicol by Tin/Reduced Graphene Oxide-Modified Screen-Printed Carbon Electrodes

A sensitive electrochemical sensor for the determination of an antibiotic chloramphenicol (CAP) in real samples was developed since they have been widely used in medicine and veterinary practice. Therefore, in this present work, tin (Sn) and reduced graphene oxide (rGO) were used to modify and to enhance the sensitivity and selectivity of a disposable screen-printed carbon electrode (SPCE), along with a fast response and a simple preparation. Transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, elemental mapping, and X-ray photoelectron spectroscopy were used to evaluate the synthesized Sn/rGO catalyst. The electrochemical performance of the Sn/rGO/SPCE was assessed for the determination of CAP under optimum conditions using differential pulse voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy. The Sn/rGO/SPCE showed two linear detection ranges at 0.5–30 μM with the linear regression Ipc (μA) = 0.3895C (μM) + 0.1599 with R2 = 0.9957 and at 30 to 100 μM with the linear regression Ipc (μA) = 0.1161C (μM) + 8.1342 with R2 = 0.9941. The limit of detection was 0.2 μM (S/N = 3) and limit of quantification was 0.7 μM (S/N = 10). The sensitivities for the lower and higher concentration ranges were 0.934 and 0.278 μA μM–1 cm–2, respectively. Additionally, the Sn/rGO/SPCE showed great selectivity and anti-interference capabilities. The sensing and disposable Sn/rGO/SPCE sensor showed a great potential for CAP analysis in milk, honey, and eye drop samples with desirable percentage recovery.