Ultrasensitive Virion Immunoassay Platform with Dual-Modality Based on a Multifunctional Aggregation-Induced Emission Luminogen

Sensitive and accurate detection of highly contagious virus is urgently demanded for disease diagnosis and treatment. Herein, based on a multifunctional aggregation-induced emission luminogen (AIEgen), a dual-modality readout immunoassay platform for ultrasensitive detection of viruses has been successfully demonstrated. The platform is relied on virions immuno-bridged enzymatic hydrolysis of AIEgen, accompanying with the in situ formation of highly emissive AIE aggregates and shelling of silver on gold nanoparticles. As a result, robust turn-on fluorescence and naked-eye discernible plasmonic colorimetry composed dual-signal is achieved. By further taking advantage of effective immunomagnetic enrichment, EV71 virions, as an example, can be specifically detected with a limit of detection down to 1.4 copies/μL under fluorescence modality. Additionally, semiquantitative discerning of EV71 virions is realized in a broad range from 1.3 × 10³ to 2.5 × 10⁶ copies/μL with the naked eye. Most importantly, EV71 virions in 24 real clinical samples are successfully diagnosed with 100% accuracy. Comparing to the gold standard polymerase chain reaction (PCR) assay, our immunoassay platform do not need complicated sample pretreatment and expensive instruments. This dual-modality strategy builds a good capability for both colorimetry based convenient preliminary screening and fluorescence based accurate diagnosis of suspect infections in virus-stricken areas.