Analyte-Induced p <i>K</i> <sub>a</sub> -Tunable Hemicyanine Dual-Locked Molecular Platform for <i>In Vivo</i> Tumor Precision Imaging
Zhangkang Lv, Jingting Huang, Jing Wang, Jinyuan Xu, Hao Feng, Xing‐Can Shen, Hua Chen
Abstract
Dual-locked probes that precisely visualize the tumor microenvironment (TME) are poised to close a critical detection gap in personalized medicine. However, traditional dual-locked systems are still constrained by sluggish response kinetics, low sensitivity, intricate design, and limited generality. To overcome these challenges, we introduce a general “analyte-induced p K a -tunable” ( AIPT ) hemicyanine dual-locked platform ( p K a -RH ) for in vivo tumor precision imaging. Interestingly, the p K a of p K a -RH can be readily modulated by adjusting the electron-donating ability of the optically tunable site. Leveraging this feature, the analyte response alters the electron-donating capacity of the recognition unit, shifting the probe’s p K a and enabling simultaneous detection of both acidity and the other biomarker. To validate the versatility of p K a -RH, we devised two dual-locked probes p K a -CE (p K a = 5.4) and p K a -Cys (p K a = 4.9), bearing acetyl (for carboxylesterase) and acrylate moiety (for Cys) recognition units that are cleaved to release p K a -RH3 (p K a = 6.6) in situ, concomitantly activating a pH response that elicits robust fluorescence enhancement. These two probes demonstrated rapid, specific, and sensitive response and high tumor-to-normal tissue ratios for hepatocellular carcinoma screening and imaging. Thus, the AIPT strategy establishes a generalizable dual-locked platform for next-generation dual-locked probes, offering a highly promising tool for intraoperative navigation and precision tumor imaging.