Visual detection of Maize chlorotic mottle virus using unmodified gold nanoparticles

Abstract

Maize chlorotic mottle virus causes corn lethal necrosis disease, and can be transmitted via infected maize seeds. It remains a challenge to detect this virus to prevent its introduction, infection and its transmission throughout fields. For this purpose, visual detection of Maize chlorotic mottle virus was investigated using unmodified gold nanoparticles (AuNPs). Detection relies on the fact that the dispersed AuNP solution is red due to the intense surface plasmon absorption band at 520 nm, whereas the AuNP solution in the presence of the species-specific probes and RT-PCR target products of Maize chlorotic mottle virus is grey blue after saline induction. After optimization of the size of the AuNPs, concentration of NaCl, probes in the reaction system and evaluation of the specificity and sensitivity of a novel assay, visual detection of Maize chlorotic mottle virus using unmodified AuNPs has been developed with simple preparation of samples in our study. Through this assay, as low as 30 pg μL⁻¹ of RNA of Maize chlorotic mottle virus was detected visually, by the naked eye, without the need for any sophisticated, expensive instrumentation and biochemical reagents. The specificity was 100% and the assay exhibited good reproducibility in 15 sample viruses. The results indicate that this assay is highly species-specific, simple, low-cost, and visual for easy detection of Maize chlorotic mottle virus in plant tissues. Therefore, visual detection of Maize chlorotic mottle virus is a potentially useful tool for middle or small-scale corporations and entry-exit inspection and quarantine bureaus to detect Maize chlorotic mottle virus in maize seeds or plant tissues.