Clustered regularly interspaced short palindromic repeats (CRISPR)-based nucleic acid detection has transformed molecular diagnostics through its speed and accuracy; however, one-pot formats are often limited by sensitivity and field suitability. Herein, we developed a universal light-controlled high-sensitivity one-pot CRISPR/Cas12a testing (ULTRAt) platform based on structure-engineered CRISPR RNA (crRNA) scaffolds. By incorporating photocaged 6-nitropiperonyloxymethyl groups into the crRNA stem-loop, Cas12a activity is transiently suppressed during isothermal amplification via structural modulation, enabling efficient target enrichment. Subsequent UV irradiation removes the protecting groups, restoring the native conformation and activating robust trans-cleavage. ULTRAt achieves a limit of detection of two copies of monkeypox virus per reaction with a 15-min time-to-result, representing a 100-fold sensitivity improvement over conventional assays. The platform further supports single-nucleotide polymorphism discrimination and human papillomavirus 16/18 genotyping. Analysis of 91 clinical samples demonstrates strong concordance between ULTRAt and reference qPCR and sequencing assays. Collectively, ULTRAt enables rapid, ultra-sensitive, and versatile one-pot detection, supporting near-patient diagnostics and genotyping.
