Penicillin biosensor based on rhombus-shaped porous carbon/hematoxylin/penicillinase.

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 (R2 = 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.