Investigation into Red Emission and Its Applications: Solvatochromic N-Doped Red Emissive Carbon Dots with Solvent Polarity Sensing and Solid-State Fluorescent Nanocomposite Thin Films

Abstract

In this work, a NIR emitting dye, p-toluenesulfonate (IR-813) was explored as a model precursor to develop red emissive carbon dots (813-CD) with solvatochromic behavior with a red-shift observed with increasing solvent polarity. The 813-CDs produced had emission peaks at 610 and 698 nm, respectively, in water with blue shifts of emission as solvent polarity decreased. Subsequently, 813-CD was synthesized with increasing nitrogen content with polyethyleneimine (PEI) to elucidate the change in band gap energy. With increased nitrogen content, the CDs produced emissions as far as 776 nm. Additionally, a CD nanocomposite polyvinylpyrrolidone (PVP) film was synthesized to assess the phenomenon of solid-state fluorescence. Furthermore, the CDs were found to have electrochemical properties to be used as an additive doping agent for PVP film coatings.

Innovations in the Solid‐State Fluorescence of Carbon Dots: Strategies, Optical Manipulations, and Applications

“…The polymer materials used for physical dispersion vary depending on the functional groups on the surface of the CDs. These polymer matrices mainly include: polyvinyl alcohol (PVA), [63][64][65][66][67][68][69][70][71][72][73] polyvinylpyrrolidone (PVP), [34,[74][75][76][77][78][79][80][81] polyvinyl butyral (PVB), [82][83][84] polymethyl methacrylate (PMMA), [30,[85][86][87][88][89][90] polydimethylsiloxane (PDMS), [91][92][93] polyethylene glycol (PEG), [32,[94][95][96] polyurethane (PU), [97,98] polyamide (PA), [99] polystyrene (PS), [100] polyvinyl carbazole (PVK), [101] and epoxy resins. [102,103] In a suitable concentration range, the polymer matrix can effectively support SSF by inhibiting the aggregation of the CDs and thus suppressing non-radiative transitions.…”

The Brown Sugar Mediated Carbon Quantum Dots as a Novel Fluorescence Sensor for Sensitive Detection of Gentamicin and Its Application in Foods

“…In recent years, CQDs (carbon quantum dots), as an emerging zero-dimensional carbon nanomaterial, have attracted much attention in the field of constructing nanosensors because of their simple synthesis method, low-cost synthesis, outstanding optical properties, and good biocompatibility [14,15]. Moreover, due to the above advantages, CQDs are also widely used in biologically relevant applications such as drug delivery, bioimaging and photothermal therapy [16][17][18][19]. The most common method for synthesizing CQDs is the one-step hydrothermal method by using readily available and inexpensive biomass as a carbon source in daily life without the use of toxic small molecule organic precursors [20,21].…”