12 - Bioimaging applications of carbon quantum dots

Abstract

Technology empowerment has served prominently in the improvement of bioimaging techniques. Developments in the bioimaging field have played a significant role in strengthening biological studies. Various techniques such as optical microscopy, fluorescence tagging, X-ray, thermal imaging, MRI, CT scan, etc. are available to capture biological events, along with various limitations. To overcome those limitations, bioimaging techniques have been linked with nanotechnology and in recent years, nanomaterials add on fascinating features in bioimaging with better resolution and fast processes. Quantum dots (QDs) are well-known for their tuneable florescence which makes them useful in many applications in medical as well as nonmedical fields. They are slowly replacing the conventional fluorophores due to their high-quality yield and stable emission for long-time imaging which are prerequisite for single molecule studies. QDs are synthesized using a wide range of elements such as zinc, silicon, lead, cadmium, and carbon. However, most of the QDs have issue in qualifying biocompatibility, as they constitute heavy metals such as lead, mercury, and cadmium. In this context, the youngest member of QDs, carbon quantum dots (cDots), has the ability to overcome this drawback. Using carbon for QDs synthesis have many benefits, both in technology as well as for environment. Apart from bioimaging, cDots have a wider range of applications such as biosensing, nanomedicine, photocatalysis, and electrocatalysis. cDots have been able to attract researchers worldwide, not just because of their easy availability or environmental concern, but especially for their excellent physical and chemical properties. Examples are its photochemical stability (resistant to photobleaching), functional flexibility, tuneable florescence emission, low cell toxicity, easy synthesis, and low cost. In this paper, we list the available options in bioimaging and discuss about cDots’ contribution in the field of bioimaging. Further, we elaborate special characteristics of cDots bioimaging along with its merit and demerits in order to examine its progress in in vivo and in vitro imaging.