Electrochemical detection of chloramphenicol in feed and soil matrices using SPCE‐N‐GQD sensors for on‐site screening applications

Chloramphenicol (CAP) is a potent antibiotic banned in many countries due to its serious health risks. Its illicit use in livestock feed can lead to contamination of meat and environmental matrices, underscoring the need for early‐stage monitoring in feed and soil. In response, we developed a green electrochemical sensing method based on cyclic voltammetry and disposable screen‐printed electrodes (t‐SPEs) for the direct detection of CAP. This system achieved a detection limit of 4.0 μg/mL (80 ng) with 85% recovery and demonstrated strong selectivity. To enhance performance, the electrodes were modified with nitrogen‐doped graphene quantum dots (N‐GQDs), resulting in the SPCE*‐(N‐GQD) sensor. This modification significantly improved sensitivity, lowering the detection limit to 0.83 μg/mL and increasing recovery rates to 95%–103%. The electrochemical characteristics of the SPCE*‐(N‐GQD) electrodes were further analyzed to elucidate the mechanisms underlying their enhanced detection capabilities. While the sensitivity of this platform is slightly lower than that of some advanced electrochemical systems, it remains sufficiently robust for routine screening of CAP in livestock feed. Overall, this simple, low‐cost, selective, and environmentally friendly approach provides a practical tool for on‐site CAP monitoring in agricultural environments.