Heterogeneous assembled nanocomplexes for ratiometric detection of highly reactive oxygen species in vitro and in vivo.

Probes for detecting highly reactive oxygen species (hROS) are critical to both understanding the etiology of the disease and optimizing therapeutic interventions. However, problems such as low stability due to autoxidation and photobleaching and unsuitability for biological application in vitro and in vivo, as well as the high cost and complex procedure in synthesis and modification, largely limit their application. In this work, binary heterogeneous nanocomplexes (termed as C-dots-AuNC) constructed from gold clusters and carbon dots were reported. The fabrication takes full advantages of the inherent active groups on the surface of the nanoparticles to avoid tedious modification and chemical synthetic processes. Additionally, the assembly endowed C-dots-AuNC with improved performance such as the fluorescence enhancement of AuNCs and stability of C-dots to hROS. Moreover, the dual-emission property allows sensitive imaging and monitoring of the hROS signaling in living cells with high contrast. Importantly, with high physiological stability and excellent biocompatibility, C-dots-AuNC allows for the detection of hROS in the model of local ear inflammation.