Facile green synthesis of nitrogen-doped carbon dots using Chionanthus retusus fruit extract and investigation of their suitability for metal ion sensing and biological applications

A Precisely Assembled Carbon Source to Synthesize Fluorescent Carbon Quantum Dots for Sensing Probes and Bioimaging Agents

“…This is resulted from uniform distribution of electron density caused by ah ydrogen-bonding network in assembled superstructures. [25] Bands due to carboxylate anions (~1560 and 1650 cm À1 )w ere identified in the carbonyl stretching region of the assembled collagen scaffold. The carbonyl stretching frequency in the spectrum was lower than that in the tropocollagen molecules (1750 cm À1 ), indicating the presenceo facarboxylate and the resulting electrostatic attraction in the assembled collagen scaffold.…”

“…The dilute (0.1 mg mL À1 )a queous solutiono fa sCQDs had an intense absorption peak in the UV regionc entered at 265 nm, which can be ascribed to the p-p*t ransition of aromatic sp 2 domainsf rom the carbonc ore, whereas the absorption tail from 300 to 800 nm was attributed to the n-p*t ransition of C=Oa nd an amine moiety on the CQDs (Figure 1f). [24,25] The absorption of asCQDs showed as ignificanti ncrease and ar edshift compared with the tcCQDs, representing ah igher yield of CQDs and electron enriching on the surface. [26] Both of the asCQDsa nd the tcCQDs (Figure 1g and FigureS1, Supporting Information) exhibited excitation-wavelength-dependent photoluminescence (PL) properties with emission peaks ranging from 426 to 490 nm at excitation from 330 to 420 nm.…”

Crown daisy leaf waste–derived carbon dots: A simple and green fluorescent probe for copper ion

“…The absorption band located at 3419 cm −1 should be attributed to the O–H and N–H groups, and the characteristic bands at 2961 cm −1 could be attributed to C–H stretching vibrations. The weak characteristic band at 1464 cm −1 could be attributed to the stretching vibrations of aromatic C–N heterocycles of the N‐CDs . The peaks at 1391 and 1090 cm −1 could be attributed to the asymmetric and symmetric stretching of C–O–C from ether or epoxy groups.…”

“…The weak characteristic band at 1464 cm −1 could be attributed to the stretching vibrations of aromatic C-N heterocycles of the N-CDs. 32 The peaks at 1391 and 1090 cm −1 could be attributed to the asymmetric and symmetric stretching of C-O-C from ether or epoxy groups. The characteristic band at 1647 cm −1 originated at the C═O group of the N-CDs.…”

Carbon source self-heating: ultrafast, energy-efficient and room temperature synthesis of highly fluorescent N, S-codoped carbon dots for quantitative detection of Fe(iii) ions in biological samples

“…Such excitationdependent emission character can be attributed to the different sizes (quantum effect) and heterogeneous surface states of N, S-codoped CDs. 51 Prior to investigating the application prospects of N, Scodoped CDs, it is necessary to rst study their photostability toward various operation environments, such as high ionic strength and extreme pH. As depicted in Fig.…”