Precision Screening and Surgical Resection of Pan‐Cancer Using a Tandem‐Locked NIR‐II Fluorescent Probe with Optimized Activation Efficiency

The development of fluorescent probes for cancer detection and imaging that balance high sensitivity, precision, and broad applicability remains a significant challenge. Although "dual-locked" probes have been devised to enhance diagnostic accuracy via two biomarkers, most fall short in sensitivity, response time, and generalizability for pan-cancer use. We address these gaps with ACy-H-NTR, a cascaded-activation, doubly quenched NIR-II probe. Engineered to respond to hypoxia and acidity-universal tumor hallmarks-it offers fast response, high sensitivity, and specificity for pan-cancer screening and imaging. In contrast to existing probes, its tandem-locked design ensures robust activation exclusively within pan-tumor microenvironments, effectively reducing false positives and delineating precise diagnostic boundaries. Its NIR-II emission and "activation-retention" mechanism enhance tumor imaging efficacy and effectively tackle issues of rapid clearance and background noise, achieving 4.9-fold higher tumor-to-normal (T/N) ratio than ICG and retaining tumor specificity for over 2 days. In pan-cancer models, it enabled high-contrast imaging (T/N ∼7.8) and precise resection with sub-2 mm margins. Crucially, it differentiates human carcinoma from adjacent tissues with sharp boundaries, confirming clinical potential. By integrating a tandem-locked and doubly quenched design that simultaneously optimizes activation efficiency, NIR-II imaging capabilities, and activation-retention mechanisms, this probe overcomes current limitations to enable precise pan-cancer identification and surgical navigation.