Development of simple, robust, and reliable detection strategy of disease biomarkers holds tremendous promise for early clinical diagnosis and prognosis of diseases. In this work, through combining a silver nanoparticle (AgNP) linked immunoassay and aggregation induced emission (AIE)-based fluorogenic Ag+ probe, we developed a silver-amplified fluorescence immunoassay for the detection of disease biomarkers. This method overcame the intrinsic limitations of enzymes as the dissolution of AgNPs generated numerous Ag+, which could switch on the fluorogenic Ag+ probe driven by tetrazolate-Ag+ complexation. As a proof of concept, our method could be used for determining α-fetoprotein (AFP) with a linear relationship in concentrations ranging from 0.1 ng mL-1 to 5 μg mL-1 and a low limit of detection of 42 pg mL-1. Our method was successfully confirmed for the detection of AFP in real serum samples from hepatocellular carcinoma (HCC) patients, demonstrating the great potential for clinical diagnosis.
Keywords: Aggregation induced emission; Biosensor; Disease biomarker; Enzyme-free amplification; Fluorescence immunoassay.
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