Advances in Red/Near infrared carbon dots in bioimaging, sensing, and phototherapeutic applications

Photoactive carbon dots (CDs) with emission in the spectral range of 600 nm to the near-infrared (NIR) region, referred to here as R/NIR CDs, are zero-dimensional nanomaterials that demonstrate good solubility in water, better photostability, and the ability to manipulate their surface. They offer superior biocompatibility for use in next-generation sensing, drug delivery, and treatment systems. Moreover, due to minimal photoluminescence (PL) interference from R/NIR CDs, along with deep tissue penetration ability and resistance to photon-induced damage, they have gained substantial popularity in challenging sectors such as tumor growth monitoring. This review captures the recent progress in this area, discussing important reports on bio and chemical sensing using R/NIR CDs, and intriguing in vivo bioimaging studies targeting tumor and cancer cells. Subsequently, the current progress in the field of phototherapy using these CDs is illustrated. We hope that this review will contribute to current advancements and assist researchers in inventing new CDs with improved properties for clinical applications.