Penicillin biosensor based on rhombus‐shaped porous carbon/hematoxylin/penicillinase

Abstract In this experiment, we designed an electrochemical sensor using penicillinase (Pen X)‐rhombus porous carbon (RPC) as the detection element and hematoxylin as the indicator to detect low concentrations of penicillin sodium (Pen G). A differential pulse voltammetry (DPV) method was used to detect Pen G in the concentration range of 10 –8 –10 –5 mg·mL –1 under optimal experimental conditions. The results showed that the peak current value and the logarithm of Pen G concentration showed a good linear relationship (R 2 = 0.9915), and the LOD was 2.68 × 10 –7 mg·mL –1 (S/N = 3). The actual milk samples were detected by the addition method and compared with the high‐performance liquid phase method; no significant difference was found in the detection results. The working electrode prepared by cross‐linking method not only extends the service life of the sensor, but also improves the sensitivity and reproducibility of the sensor. It can also be used to detect the Pen G residue in the actual milk samples repeatedly. Practical Application In this study, an electrochemical sensor for the rapid detection of penicillin sodium in milk was prepared, which has good sensitivity and fast detection speed.