Carbon dots(CDs)are fluorescent carbon-based nanomaterials with sizes smal-ler than 10 nm,that are renowned for their exceptional properties,including superior anti-photobleaching,excellent biocompatibility,and minimal toxicity,which have received sig-nificant interest.Near-infrared(NIR)light has emerged as an ideal light source in the biolo-gical field due to its advantages of minimal scattering and absorption,long wavelength emission,increased tissue penetration,and reduced interference from biological back-grounds.CDs with efficient absorption and/or emission characteristics in the NIR spectrum have shown remarkable promise in the biomedical uses.This study provides a comprehens-ive overview of the preparation methods and wavelength modulation strategies for near-in-frared CDs and reviews research progress in their use in the areas of biosensing,bioimaging,and therapy.It also discusses current challenges and clinical prospects,aimed at deepening our understanding of the subject and promoting further advances in this field.
become an outstanding type of theranostic probe because of tunable luminescence,superior pharmacokinetics,low toxicity,and rich surface chemistry.The second near-infrared(NIR-Ⅱ)luminescence offers unique merits,such as deep tissue penetration,high spatial resolution,and admirable signal-noise ratio,creating many opportunities and challenges for ultrasmall AuNPs in advanced biomedical applications.Herein,this review illustrates the recent advances of ultrasmall AuNPs in understanding the NIR-Ⅱ mechanisms,clearance pathways,and related biomedical applications.We firstly elucidate the present understanding of the NIR-Ⅱ mechanisms of ultrasmall AuNPs,along with some effective strategies for enhancing NIR-Ⅱ luminescence,namely heterometal doping and surface rigidification.Then,we discuss the impact of their structures on liver clearance and kidney clearance.Further,we highlight the major biomedical applications of these ultrasmall AuNPs in bioimaging,antibacterial,nanomedicine,and drug delivery.Finally,we offer some outlooks on the challenges and chances of ultrasmall AuNPs for later research endeavors to promote their clinical translation in the biomedical field.
