A Simple Paper-Based Lab-on-a-Chip for the Detection of a Highly Pathogenic Strain of Porcine Reproductive and Respiratory Syndrome Virus

Abstract

A paper-based laboratory-on-a-chip assay for the rapid detection of a highly pathogenic strain of porcine reproductive and respiratory syndrome virus (HP-PRRSV) was developed for the first time. The single-unit chip was simply fabricated using Whatman filter paper and plastic lamination. The chip measured 2.5 × 3.0 cm2 and was divided into two parts, one for nucleic acid amplification and the other for signal detection. The HP-PRRSV assay was performed by specific ORF I Nsp 2 gene amplification via an isothermal reverse transcription loop-mediated DNA amplification platform, whereas the cDNA signal detection was performed by visual observation of colorimetric changes in blue silver nanoplates (AgNPls). Positive results caused non-aggregation of the blue AgNPls on the detection pad, whereas negative results induced colorimetric changes in the AgNPls from blue to colourless on the pad. The assay had a limit of detection of 100 copies of the target Nsp 2 gene and high specificity for other types of infectious viruses. The assay required only one hour to complete. This work demonstrates a simple and rapid assay for viruses using a simple, low-cost, paper-based chip.