A biotin-guided two-photon fluorescent probe for detection of hydrogen peroxide in cancer cells ferroptosis process

Hydrogen peroxide (H 2 O 2 ) plays a vital role in organism due to its strong oxidizability, especially in resisting the invasion of pathogens. Cancer cells have abnormal concentrations of hydrogen peroxide due to their disordered reproduction. In complex biological systems, however, conventional fluorescent probes based solely on their fluorescent response to abnormal H 2 O 2 overexpression in cancer cells are not enough to distinguish cancer cells from other unhealthy or immune cells. Therefore, it is necessary to develop other methods to allow the probe to selectively enter the cancer cells and perform fluorescence imaging of the hydrogen peroxide in the cancer cells. Herein, we developed a biotin-guided, two-photon fluorescent probe ( BT-HP ) for sensitive detection of H 2 O 2 in cancer cells. Through the study on the properties of the probe, it was found that the probe can selectively enter cancer cells. The depth penetration imaging of H 2 O 2 in cancer cells and tumor tissues by two-photon microscope proves the potential of the probe BT-HP as a tumor targeting H 2 O 2 biosensor. The probe was further applied to detect hydrogen peroxide in cancer cells during the ferroptosis process. • Selectively enrichment in cancer cells using tumor-targeted delivery method. • Has a large turn-on fluorescence signal (40-fold enhancement). • Imaging exogenous and endogenous H 2 O 2 in cancer cells and tumor tissue. • Imaging H 2 O 2 in ferroptosis process of cancer cells.