Catalytic Immunoassay with Fluorescence-Colorimetric Dual Readout for Highly Sensitive Zika Virion Detection

Abstract Zika virus (ZIKV) infection may induce severe neurological disorders and congenital malformations in pregnant women and fetuses, posing a substantial threat to global public health. Therefore, sensitive, accurate, and convenient detection strategies are essential for early ZIKV diagnosis to block viral transmission and mitigate adverse clinical complications. Herein, a robust fluorescence-colorimetric dual-modal immunoassay was successfully developed for high-performance ZIKV detection based on dual-functional fluorescence nanoprobes grafted with ZIKV antibodies and catalase. The elaborately designed nanoprobes can generate stable fluorescence signals to realize precise fluorescence-based quantitative detection. Meanwhile, the modified catalase can efficiently decompose hydrogen peroxide, thereby modulating the morphological transformation of gold nanoparticles and achieving naked-eye visible plasmonic colorimetric analysis, with a low limit of detection down to 0.85 PFU/μL. Benefiting from the complementary dual-signal outputs and mutual verification mechanism, the proposed method effectively avoids signal interference and detection errors inherent to conventional single-mode assays. Clinical specimen validation verified that this dual-modal immunoassay achieves 100% diagnostic accuracy in practical ZIKV detection. Integrating high sensitivity, visual readout, excellent anti-interference ability, and reliable quantitative performance, this dual-modal sensing platform provides a promising strategy for early clinical diagnosis and epidemiological surveillance of ZIKV infections.