A smartphone-based portable biosensor for colorimetric detection of porcine reproductive and respiratory syndrome virus

Porcine reproductive and respiratory syndrome virus (PRRSV) causes serious impacts on livestock farms worldwide, especially in the big pig-raising country of China. Development of fast and accurate PRRSV assay is of great significance in early diagnosis of PRRSV infection, which helps control large-scale disease transmission. Herein, we develop a portable and universal colorimetric biosensor for rapid detection of PRRSV with a smartphone-based platform. In the presence of target sequence, a sandwich structure is formed to anchor polydopamine-silver nanoparticles with pH indicators on cotton swabs. The amplified visual information can be captured and analyzed for accurate quantification within the range from 10 pM to 1 mu M. Excellent analytical results are also validated challenging real tissue samples from PRRSV infected pigs. Meanwhile, the biosensor can be extended for nervous necrosis virus (NNV) detection from Plectropomus leopardus, demonstrating its great universal utility.