Rhodamine B/gold nanoparticles-coloaded UiO-66 as a novel probe for highly sensitive and dual-mode detection of Potato virus S in field samples

IntroductionPotato virus S (PVS) causes severe damage to Solanaceae plants, especially potato, due to its widespread infection and the reliance on laboratory-based reverse transcription-polymerase chain reaction (RT-PCR) testing. This work intends to develop a rapid, highly sensitive, and dual-signal platform for on-site PVS detection.MethodsWe developed a highly sensitive lateral-flow immunoassay (LFIA) capable of colorimetric and fluorescent dual-mode detection based on a novel core-shell structured probe, which consists of a porous metal-organic framework UiO-66 encapsulating rhodamine B inside and loading gold nanoparticles (AuNPs) outside with 3-aminopropyltriethoxysilane (APTES) as a spacer and glue, denoted as UR@APTES@AuNPs.ResultsThe developed LFIA enabled dual-mode PVS detection within 15 min with negligible cross-interference from Potato virus X and Potato virus Y. The platform achieved a limit of detection (LOD) of 31.2 pg/mL for the colorimetric mode and 7.6 pg/mL for the fluorescent mode, over one order of magnitude lower than the conventional AuNPs-based LFIA (LOD = 462.4 pg/mL). Furthermore, PVS in field-collected potato leaves was successfully detected by the new LFIA platform.DiscussionThe dual-mode LFIA demonstrated a rapid, cost-effective, and highly sensitive on-site screening of PVS in field samples, highlighting its great potential in practical application. This platform can be easily adapted to the detection of other pathogenic viruses by using the corresponding specific antibodies.