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, HD-Zn, designed to detect Zn²⁺ in relation to CVDs. We developed a novel fluorescence probe, HD-Zn, by conjugating N,N-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. In vivo imaging in mouse models showed decreased fluorescence intensity in the aorta with disease progression. Our findings confirm that HD-Zn 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.