A melatonin-based targetable fluorescent probe activated by hydrogen peroxide for tumor cells screening

Early treatment is the best choice for cancer treatment. But there are many difficulties in the early diagnosis of cancer. Fluorescent probes can be used to detect small molecules or proteins overexpressed in tumor cells as a screening tool for tumor cells. However, many analytes are not specifically expressed in tumor cells. Therefore, the sensitivity and accuracy are both limited. Previous studies have shown that hydrogen peroxide (H2O2) is overexpressed in tumor cells. Similarly, melatonin can effectively bind to G-protein coupled receptors (MT1 and MT2), which are also overexpressed in some types of tumor cells. Hence, we constructed a novel melatonin-based targetable H2O2 fluorescent probe for precisely screening tumor cells. The results showed that the proposed probe can successfully detect endogenous and exogenous H2O2 in living cells and zebrafish, and accurately screen tumor cells. Importantly, this work not only proves the potential targeting capability of melatonin for tumor cells, but also provides new strategy of targeting plus activation for tumor cells screening. Moreover, the proposed probe in this work can serve as a potential tool for early diagnosis of cancer.