Photoelectrochromic sensing chip with recombinase polymerase amplification for visual detection of African swine fever virus

The trace, portable, and rapid detection of African swine fever virus (ASFV) is of significant importance for monitoring and controlling the spread of the epidemic. Hence, the development of a rapid, simple and intuitive ASFV sensitive detection method has become the focus of research. To overcome the limitations of detection scenarios, complex reaction device and signal acquisition device, a bismuth sulfide/bismuth metal-organic framework (Bi2S3/Bi MOF) modified photoelectrochromic sensing chip was prepared to realize high sensitivity, convenience and visual detection of ASFV based on the detection technology of recombinase polymerase amplification (RPA). In this work, the photoactive material Bi2S3/Bi MOF was employed to improve the sensitivity of the photoelectrochromic visual sensing chip, prussian blue (PB) was used as the discoloration material for visual detection and the smartphone was used for accurate RGB detection. By screening the RPA amplification sequences of with ASFV characteristics, the forward primers were modified by amination and fixed to the surface of the Bi2S3/Bi MOF modified electrode for RPA amplification. When the photogenerated electrons of Bi2S3/Bi MOF were injected into PB, PB could be reduced to Prussia white, so the detection of ASFV targets with different concentrations can be realized through the color change of PB with the detection limit of 1.7 x 10 _ 12 g/L (2.72 copies/mu L). The photoelectrochromic visual sensing chip shows good specificity and stability, and does not necessitate complex instruments, and plays an important role in the actual field application of African swine fever epidemic prevention and control and monitoring.