An endoplasmic reticulum-targeted near-infrared probe for monitoring HClO fluctuation in diabetic mice and human blood

Hypochlorous acid (HClO) is a key signal molecule involved in various physiological and pathological processes as well as the immune system. Recent study demonstrated that excess HClO in the body is closely related to diabetes since it can induce stress in the endoplasmic reticulum (ER). Unfortunately, up to now, developing a near-infrared (NIR) fluorescent probe that can detect ER HClO remains a challenge. Herein, we designed and synthesized NIR-ER-HClO, which stains ER with high selectivity, sensitivity, and hypotoxicity. The probe could accurately monitor exogenous and endogenous HClO variations in living cells. Besides, NIR-ER-HClO was successfully used to image HClO in a diabetic mice model. Compared with the control group, NIR-ER-HClO showed a stronger NIR fluorescence signal in diabetic mice and in the blood of people with diabetes. Thus, NIR-ER-HClO provides an effective method for diagnosing ER HClO in related diseases.