CRISPR/Cas12a-based dual-modal signal platform using MIL-101(Fe) for colorimetric and electron spin resonance detection of HPV-16 nucleic acid.

Human papillomavirus (HPV) infection is a leading cause of cervical cancer and other malignancies, underscoring the urgent need for accurate and rapid early diagnostic strategies. Herein, we report a dual-mode colorimetric and electron spin resonance (ESR) method for the qualitative detection of HPV-16, based on the integration of the CRISPR/Cas12a system with a metal-organic framework (MOF). A peroxidase-mimicking iron-based MOF, designated MIL-101(Fe), was conjugated to magnetic beads via a single-stranded DNA linker to serve as a signal probe. Upon recognition of the target nucleic acid, MIL-101(Fe) catalyzes the decomposition of hydrogen peroxide to generate hydroxyl radicals, which oxidize a chromogenic substrate to produce a visible color change. Meanwhile, the generated radicals are captured by a spin trap and detected by ESR spectroscopy. The assay enables sensitive and rapid detection of HPV-16, with clear discrimination even in mixtures containing both HPV-16 and HPV-18. Importantly, when evaluated with clinical specimens, the method achieved 100% sensitivity and specificity. Overall, this work provides a feasible and promising strategy for ultrasensitive nucleic acid detection and offers a new avenue for advancing CRISPR-based multimodal diagnostic platforms toward practical applications.