Programmable molecular microscopy: CRISPR/Cas fluorescent probes revolutionizing spatiotemporal genomic imaging

Bioimaging technologies visually resolve spatiotemporal dynamics of biomolecules, cells, and tissues, enabling essential insights into gene regulation, disease mechanisms, and drug metabolism. CRISPR/Cas-based fluorescent probes transform CRISPR from "genetic scissors" into "molecular microscopes," providing an indispensable tool for in situ decoding of molecular events in living systems. Their high nucleic acid specificity establishes CRISPR/Cas as a pivotal technology for dynamically monitoring genomic and transcriptomic events at live-cell and in vivo levels. This work systematically outlines design strategies and functional mechanisms of mainstream CRISPR/Cas fluorescent probes for bioimaging, encompassing five categories: fluorescent proteins, synthetic dyes, smart gated probes, nanomaterials, and multimodal integrated probes. Recent advances and persistent challenges in achieving high-sensitivity targeted imaging, effective signal amplification, and precise delivery control are comprehensively examined, including analysis of their advantages, limitations, and adaptability in complex biological environments. Building on breakthroughs in in vivo delivery systems, diverse carriers demonstrate significant potential for enhancing CRISPR/Cas transport efficiency, improving tissue penetration, and enabling spatiotemporal controlled release. Continued innovation drives CRISPR/Cas imaging platforms toward higher sensitivity, enhanced biocompatibility, and multifunctional integration, thereby fostering the convergence and broad application of gene editing and molecular diagnostics.