Multifunctional\nOptical Sensor for the Comprehensive\nDetection of Zinc Ions in Cardiovascular Disease

Cardiovascular diseases (CVDs) are a major global health\nconcern,\nhighlighting the need for effective diagnostic tools. Zinc ions (Zn<sup>2+</sup>) play a role in CVDs, but their detection is challenging.\nThis study presents a multifunctional optical sensor, <b>HD-Zn</b>, designed to detect Zn<sup>2+</sup> in relation to CVDs. We developed\na novel fluorescence probe, <b>HD-Zn</b>, by conjugating <i>N,N</i>-di(2-picolyl)ethylenediamine (DPEN) to HD via an amide\nbond, which results in fluorescence quenching due to photoinduced\nelectron transfer (PeT). Adding Zn<sup>2+</sup> significantly increased\nfluorescence intensity in the near-infrared region (NIR-I). The probe\nshowed a linear response to varying Zn<sup>2+</sup> concentrations,\nwith a detection limit of 9.8 nM, appropriate for physiological conditions.\nFluorescence imaging in RAW264.7 macrophages indicated lower intracellular\nZn<sup>2+</sup> levels in foam cells compared to healthy cells, linked\nto CVDsprogression. <i>In vivo</i> imaging in mouse models\nshowed decreased fluorescence intensity in the aorta with disease\nprogression. Our findings confirm that <b>HD-Zn</b> is a reliable\ntool for measuring Zn<sup>2+</sup> levels in plaques and demonstrate\nits biosafety for detecting Zn<sup>2+</sup> in serum and urine, offering\npotential for clinical applications in CVDs diagnosis and monitoring.