Magnetic Micro/nanorobots for biological detection and targeted delivery

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-polyethylene-glycol (DSPE-PEG) to construct a autocatalytically-activatable PA sensor (FeMoOx@[email protected]). In its presence, ABTS can be converted into oxidized ABTS·+ by H2O2. ABTS·+ 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@[email protected] 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.