The Role of Glutathione and Ethanol in Dictating the Emission Dynamics of Natural Resources‐Derived Highly Luminescent Carbon Nanodots

Abstract

An integrative approach is adopted to address the intriguing aspect of fluorescence dynamics in carbon nanodots (CNDs). In this contribution, we offer two different types of highly luminescent CNDs derived from a natural‐resource and glucose‐amine‐CTAB reactions by employing fast and cost‐effective methods. Lemon‐juice derived CNDs (CND1) exhibit excitation‐independent emission, whereas the other one shows excitation‐dependent fluorescence; the former one possesses more of a nanosheet like structure whereas later exhibit particle behavior. We also provide conclusive evidence on the existence of the CNDs in a state of aggregation in aqueous solution and the presence of high molecular weight structure, contrary to reported observations. Circular dichroism studies suggest strong H‐bonding networks in CNDs. The juxtaposition of experimental findings indicates the presence of pyrrolopyridine‐type fluorophoric moiety. The temperature‐dependent luminescence properties of CNDs is highly reversible in nature therefore, synthesized CNDs can find potential application as nanothermometer. Metal‐ion dependent modulation of fluorescence properties of CND1 suggest its applications in ion‐sensing.

Connecting the Dots of Carbon Nanodots: Excitation (In)dependency and White-Light Emission in One-Step

“…And the hypothesis of aggregation demands the understanding of the aggregation in homogeneous solvent, specifically in spectroscopic terms. Nevertheless, such understanding cannot remain indifferent from the emergence of the nanodot exhibiting excitation-independent emission, a typical molecular behavior. − The excitation dependency is found to be highly dependent on precursors. Thus, the breaking of the Kasha–Vavilov rule seems to be dependent on precursors chosen for the synthesis and not on the existence of carbon lattice spacing generally observed under an electron microscope.…”

N-Doped Yellow-Emissive Carbon Nanodots from Gallic Acid: Reaction Engineering, Stimuli-Responsive Red Emission, and Intracellular Localization

“…And the transition in the low-energy region is found to be predominantly between the HOMO and LUMO. However, a difference of 26 nm in band maxima is due to the omission of specific interactions such as solvation, solute–solvent interactions, and H-bonding. − Considering the presence of the basic amino group in the molecule, we have also optimized the geometry (Table S5) of the protonated form (monocationic) of the molecule (Figure C). A significant change in dipole moments between the neutral (4.2 D) and protonated (9.6 D) forms has been noticed, which may influence the time-resolved emission properties such as the solvation of the molecule.…”

Evolution of Micron-Spaced Patterns within Precipitating Patterns of In Situ Synthesized Silver Nanoparticles in a Nanodot-Embedded PVA/PVP Film

“…Nanodots used in this study are primarily reductive in nature; hence, the activation energy associated for nucleation and subsequent growth of Ag NPs is much lower . The reaction–diffusion equations of this system can be written as follows where R is the reaction rate, θ is the rate coefficient of both nucleation and growth, D stands for the diffusion coefficient of species, and ∇ 2 is the Laplacian operator.…”

“…Subsequently, the autoclave was cooled to room temperature. The color of the solution changed to orange-brown from whitish, indicating the formation of carbon nanodots …”

“…Carbon dots are an emerging class of carbon nanomaterial for their unique optoelectronic properties and water solubility. In this study, the properties of two CNDs have been investigated, which are obtained from different synthetic methods using distinctly different precursors. − CND1 is synthesized by the hydrothermal method using lemon extract and glutathione as precursors, whereas CND2 is obtained from a heating method using glucose and lysine as starting materials. The reported studies are carried out at a much faster time-scale; hence, the underlying processes involved in the precipitation of Ag NPs cannot be resolved.…”