Polymeric carbon nitride-based materials: Rising stars in bioimaging

Polymeric carbon nitrides (CN), due to their unique physicochemical properties, versatile surface functionalization, ultra-high surface area, and good biocompatibility, have attracted considerable interest in diverse biomedical applications, such as biosensors, drug delivery, bioimaging, and theranostics. In this review, the recent advances in bioimaging of CN-based nanomaterials are summarized according to the imaging modalities, including optical (fluorescence and Raman) imaging, magnetic resonance imaging (MRI), photoacoustic imaging (PAI), computed tomography (CT), and multimodal imaging. The pros and cons of CN bioimaging are comprehensively analyzed and compared with those in previous reports. In the end, the prospects and challenges of their future bioimaging applications are outlooked.