Preparation and application of colloidal gold test paper for the detection of multiple tobacco viruses

To establish a rapid, specific and simple method for detecting tobacco virus, a colloidal gold labeling technique and immunochromatography were incorporated into paper-based test strips to target two (TMV-CMV, CMV-PVY and TMV-PVY) or three (TMV-CMV-PVY) viruses. The results showed that the test paper for the detection of three viruses had good sensitivity and specificity. The minimum detectable concentrations for TMV, CMV and PVY were 1.02-10.2, 1.10-11.0 and 1.20-12.0 ng/mL, respectively. No cross reaction between TMV, CMV, PVY and TEV, PVA, TSWV were found with the test paper for these harmful tobacco viruses. Tobacco seedlings in greenhouses were also subjected with the test paper, and the coincidence rate was above 90% between the detected results using the test paper and a RT-PCR technique.