An autocatalytically-activatable hydrogen peroxide photoacoustic sensor for in situ visualization precise diagnosis and drug intervention tracing in diabetes syndrome

In situ visualization for the diagnosis of diabetic syndrome and visual monitoring the response to drug treatment is a challenge. Herein, we designed and prepared an autocatalytically-activatable hydrogen peroxide photoacoustic (PA) sensor. We first prepared the FeMoOx nanoparticle with catalase activity, then combined it to 2,2'-azino-bis(3-ethylbenzothi-azoline-6-sulfonic acid) (ABTS) and distearoylphos-phoethanola-mine-polyethyleneglycol (DSPE-PEG) to construct a autocatalytically-activatable PA sensor (FeMoOx@ABTS@DSPE-PEG). In its presence, ABTS can be converted into oxidized ABTS(center dot+) by H2O2. ABTS(center dot+) exhibits strong light absorption in the near-infrared region, and can serve as an ideal contrast agent for PA imaging. H2O2 as a biomarker of oxidative stress response is closely related to the occurrence and development of diabetes mellitus and its complications. Therefore, FeMoOx@ABTS@DSPE-PEG was used as a PA sensor of H2O2 for visual monitoring of the progression of diabetes-induced liver injury and metformin-mediated treatment of diabetes. The autocatalytically-activatable PA sensor developed in this study provides a promising platform for in situ visual diagnosis of diabetes and its syndrome and monitoring the response to therapy.