Accurate and ultrasensitive detection for PEDV based on photoelectrochemical sensing coupling loop-mediated isothermal amplification

Porcine epidemic diarrhea (PED) is a serious disease requiring a simple and accurate detection method. Accordingly, this study developed a novel, ultrasensitive photoelectrochemical (PEC) sensing platform using the loop-mediated isothermal amplification (LAMP) technique (LAMP-PEC). An amino (−NH 2 )-modified LAMP product is obtained by amplification of the PED virus gene with specially designed primers. The generated NH 2 -modified LAMP product is assembled on the surface of an electrode by forming imine linkages between aldehyde and amino groups based on the Schiff base reaction. A stable photocurrent is provided by a CdIn 2 S 4 photoactive material, which possesses high photoelectric conversion efficiency. Amplified DNA assembled on the electrode surface increases steric hindrance and hinders electrons from moving from the electrode to electron acceptors , which decreases the photocurrent. This strategy can detect PEDV with a low detection limit of 0.3 fg μL −1 and a wide linear range of 1 × 10 −3 -1 × 10 2  pg/μL. The sensing platform has excellent specificity and sensitivity and can be used for the quantitative detection of many other pathogens with the assistance of LAMP.