Computational Investigation of Interactions between Carbon Nitride Dots and Doxorubicin

The study of carbon dots is one of the frontiers of materials science due to their great structural and chemical complexity. These issues have slowed down the production of solid models that are able to describe the chemical and physical features of carbon dots. Recently, several studies have started to resolve this challenge by producing the first structural-based interpretation of several kinds of carbon dots, such as graphene and polymeric ones. Furthermore, carbon nitride dot models established their structures as being formed by heptazine and oxidized graphene layers. These advancements allowed us to study their interaction with key bioactive molecules, producing the first computational studies on this matter. In this work, we modelled the structures of carbon nitride dots and their interaction with an anticancer molecule (Doxorubicin) using semi-empirical methods, evaluating both geometrical and energetic parameters.

An Overview on Carbon Quantum Dots Optical and Chemical Features

Carbon quantum dots are the materials of a new era with astonishing properties such as high photoluminescence, chemical tuneability and high biocompatibility. Since their discovery, carbon quantum dots have been described as nanometric high-fluorescent carbon nanoparticles, but this definition has become weaker year after year. Nowadays, the classification and the physical explanation of carbon quantum dots optical properties and their chemical structure remain matter of debate. In this review, we provide a clear discussion on these points, providing a starting point for the rationalization of their classification and a comprehensive view on the optical and chemical features of carbon quantum dots.

Hot-Tailoring of Carbon Nitride Dots with Redshifted Photoluminescence for Visual Double Text Encryption and Bioimaging

The fabrication of carbon dots and their doped forms by top-down chemical cleavage has attracted considerable attention in the efforts to meet the increasing demands for optoelectronic applications ranging from biosensing to electro- and photocatalysis. However, due to strong quantum confinement effects, the size decrease often leads to an increase in the band gap, even in the emission of deep-ultraviolet (DUV) light, which greatly limits their applications. Here, we report a facile hot-tailoring strategy for fabricating carbon nitride nanodots (CNDs) with redshifted intrinsic photoluminescent (PL) emission, compared with the pristine bulk precursor. It has been found that the different leaving abilities of the C,N-containing groups during the pyrolysis stage and the chemical passivation during the liquid-collection stage played vital roles. Due to the redshifted photoluminescence and other attractive features, the as-obtained CNDs were successfully applied in visual double text encryption with higher security and also in bioimaging with photostability superior to traditional dyes. This work highlights the great potential of the hot-tailoring method in modulating carbon-based nanostructures and offsetting band-gap widening as the size decreases.

Carbon Nanodots as Peroxidase Nanozymes for Biosensing

'Nanozymes', a term coined by Scrimin, Pasquato, and co-workers to describe nanomaterials with enzyme-like characteristics, represent an exciting and emerging research area in the field of artificial enzymes. Indubitably, the last decade has witnessed substantial advancements in the design of a variety of functional nanoscale materials, including metal oxides and carbon-based nanomaterials, which mimic the structures and functions of naturally occurring enzymes. Among these, carbon nanodots (C-dots) or carbon quantum dots (CQDs) offer huge potential due to their unique properties as compared to natural enzymes and/or classical artificial enzymes. In this mini review, we discuss the peroxidase-like catalytic activities of C-dots and their applications in biosensing. The scope intends to cover not only the C-dots but also graphene quantum dots (GQDs), doped C-dots/GQDs, carbon nitride dots, and C-dots/GQDs nanocomposites. Nevertheless, this mini review is designed to be illustrative, not comprehensive.