Miniaturized Paper-Based Smartphone Biosensor for Differential Diagnosis of Wild-type Pseudorabies Virus Infection versus Vaccination Immunization

Abstract

Porcine pseudorabies is one of the most serious infectious diseases influencing the pig-breeding industry. It inflicts enormous losses, underscoring the urgent need for the development of a clinical method for accurate and quick diagnosis of wild-type PRV infection. PRV-gE antibodies are an excellent indicator of PRV source, as their presence in the serum of individuals infected by wild-type PRV but not in those administered PRV gE-deleted vaccines enables distinction of wild-type PRV infection from vaccine immunization. For this study, we developed a miniaturized paper-based smartphone biosensor detection system (paper-biosensor) based on a blocking immunoassay for differential diagnosis of wild-type pseudorabies virus infection versus vaccination immunization. Latex beads (LBs) were used to label PRV, and the test line (T-line) was coated with PRV gE-mAb. The ambient light sensor of the smartphone was used to measure the transmitted light intensity from the T-line. Under optimized conditions, the paper-based smartphone biosensor achieved excellent sensitivity and selectivity. In tests of swine clinical samples (n = 101), the agreement between this method and the most widely used commercial gE-ELISA kit was 98%. Moreover, our method was rapid (15 min), low cost, and easy to operate, endowing it with great promise as an on-site differential diagnosis tool for PRV infection.