Multifunctional Optical Sensor for the Comprehensive Detection of Zinc Ions in Cardiovascular Disease

Cardiovascular diseases (CVDs) are a major global health concern, highlighting the need for effective diagnostic tools. Zinc ions (Zn²⁺) play a role in CVDs, but their detection is challenging. This study presents a multifunctional optical sensor, <b>HD-Zn</b>, designed to detect Zn²⁺ in relation to CVDs. We developed a novel fluorescence probe, <b>HD-Zn</b>, by conjugating <i>N,N</i>-di(2-picolyl)ethylenediamine (DPEN) to HD via an amide bond, which results in fluorescence quenching due to photoinduced electron transfer (PeT). Adding Zn²⁺ significantly increased fluorescence intensity in the near-infrared region (NIR-I). The probe showed a linear response to varying Zn²⁺ concentrations, with a detection limit of 9.8 nM, appropriate for physiological conditions. Fluorescence imaging in RAW264.7 macrophages indicated lower intracellular Zn²⁺ levels in foam cells compared to healthy cells, linked to CVDsprogression. <i>In vivo</i> imaging in mouse models showed decreased fluorescence intensity in the aorta with disease progression. Our findings confirm that <b>HD-Zn</b> is a reliable tool for measuring Zn²⁺ levels in plaques and demonstrate its biosafety for detecting Zn²⁺ in serum and urine, offering potential for clinical applications in CVDs diagnosis and monitoring.