Fluorescent carbon dots were prepared via a simple and straightforward one-step pyrolytic process using N-hydroxysuccinimide. The prepared C-dots present remarkable photoluminescence with blue to green shifting emission and absolute quantum yields varying from 14 to 31% as a function of the excitation wavelength and selected dispersion media. Interestingly, up-conversion from NIR to the visible range was not only instrumentally recorded but even visually observable. Further, the composition and morphology of the prepared C-dots were studied using XPS, FT-IR, Raman, P-XRD, DLS and AFM as investigation methods. Since the majority of C-dot studies are biased towards fluorescent labeling in cellular imaging, their photoluminescence properties, physicochemical stability and ease of fabrication are expected to play a key role in applications ranging from sensors to efficient solar energy conversion or high performance optoelectronic devices.

The aim of this study was to determine the effects of main factors and interactions on the color removal performance from dye solutions using the electrocoagulation process enhanced by adsorption on Granular Activated Carbon (GAC). In this study, a mathematical approach was conducted using a two-level fractional factorial design (FFD) for a given dye solution. Three textile dyes: Acid Blue 74, Basic Red 1, and Reactive Black 5 were used. Experimental factors used and their respective levels were: current density (2.73 or 27.32 A/m²), initial pH of aqueous dye solution (3 or 9), electrocoagulation time (20 or 180 min), GAC dose (0.1 or 0.5 g/L), support electrolyte (2 or 50 mM), initial dye concentration (0.05 or 0.25 g/L) and current type (Direct Current—DC or Alternative Pulsed Current—APC). GAC-enhanced electrocoagulation performance was analyzed statistically in terms of removal efficiency, electrical energy, and electrode material consumptions, using modeling polynomial equations. The statistical significance of GAC dose level on the performance of GAC enhanced electrocoagulation and the experimental conditions that favor the process operation of electrocoagulation in APC regime were determined. The local optimal experimental conditions were established using a multi-objective desirability function method.

Background: Theranostics, a novel concept in medicine, is based on the use of an agent for simultaneous diagnosis and treatment. Nanomaterials provide promising novel approaches to theranostics. Carbon Dots have been shown to exhibit anti-tumoral properties in various cancer models. The aim of the present study is to develop gadolinium, Fe³⁺, and Mn²⁺-doped N-hydroxyphthalimide-derived Carbon Dots. The resulted doped Carbon Dots should preserve the anti-tumoral properties while gaining magnetic resonance imaging properties. Methods: Normal and cancer cell lines have been treated with doped Carbon Dots, and the cell viability has been measured. The doped Carbon Dots that exhibited the most prominent anti-tumoral effect accompanied by the lowest toxicity have been further in vivo tested. Magnetic resonance imaging evaluates both in vitro and in vivo the possibility of using doped Carbon Dots as a contrast agent. Results: According to the results obtained from both the in vitro and in vivo experimental models used in our study, Mn²⁺-doped Carbon Dots (Mn-CDs-NHF) exhibit anti-tumoral properties, do not significantly impair the cell viability of normal cells, and reduce lung metastasis and the volume of mammary primary tumors while allowing magnetic resonance imaging. Conclusions: Our findings prove that Mn-CDs-NHF can be used as theranostics agents in pre-clinical models.