ScholarWorks@중앙대학교

초록

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne pathogen associated with high mortality and an expanding endemic range, underscoring the critical demand for rapid, sensitive, and reliable diagnostic strategies. Nevertheless, currently available antibody-based immunoassays suffer from intrinsic drawbacks, such as high manufacturing costs, poor thermal stability, and limited diagnostic sensitivity during the early phase of infection. To address these challenges, we developed a highly sensitive colorimetric detection platform that employs chemically engineered M13 bacteriophages as molecular receptors for SFTSV antigen sensing. High-affinity phage clones targeting the SFTSV Gn glycoprotein were identified through phage display, and their pVIII major coat proteins were selectively functionalized via amine-reactive NHS-activated biotin linkers with differing spacer lengths and flexibilities (NHS-Biotin, NHS-LC-Biotin, and NHS-PEG(1)(2)-Biotin). The results demonstrate that incorporation of a flexible PEG12 spacer effectively alleviates steric hindrance on the densely packed pVIII surface, thereby increasing biotin accessibility and enhancing streptavidin-HRP-mediated signal amplification. MALDI-TOF analysis confirmed efficient biotinylation under the optimized reaction conditions, while TEM imaging verified that the overall phage morphology was preserved following chemical modification. Under these optimized conditions, the platform generated a clear concentration-dependent colorimetric response to the Gn antigen across the range of 1.56-12.5 nM, exhibiting strong linearity (R & sup2; = 0.96) and a limit of detection of 1.67 nM. This engineered phage-based system represents a structurally rational alternative to conventional antibody platforms and offers a scalable strategy for sensitive and cost-effective SFTSV antigen detection.

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