Microwave-assisted synthesis of luminescent and biocompatible lysine-based carbon quantum dots

pH/Redox‐Triggered Photothermal Treatment for Cancer Therapy Based on a Dual‐Responsive Cationic Polymer Dot

“…The FA‐CD system without an ICG compartment (control) shows blue emission at an excitation wavelength of 360 nm, and it is enhanced at high concentrations of GSH as a result of cleavage of the disulfide bonds, which results in a decrease in the size of the small particles (Figure S2). In the present study, the pH/redox‐controlled release capability of ICG‐CD nanoparticles between normal and tumor environments was determined by FRET‐stimulated fluorescence off/on changes at an excitation wavelength of 360 nm by adjusting the pH and GSH concentration . As shown in Figure a, for a ICG‐CD solution at neutral pH without GSH, the fluorescent intensity of ICG‐CD does not show any significant emission, and this is indicative of the formation of a ICG‐CD complex, which effectively blocks the emission by energy transfer.…”

“…In the present study, the pH/redox-controlled releasec apability of ICG-CD nanoparticles between normal and tumor environments was determined by FRET-stimulated fluorescenceo ff/on changes at an excitation wavelength of 360 nm by adjusting the pH and GSH concentration. [29] As shown in Figure 2a,f or aI CG-CD solution at neutralp Hw ithoutG SH, the fluorescent intensity of ICG-CD does not show any significant emission, and this is indicative of the formationo faICG-CD complex, which effectively blocks the emission by energy transfer.T he pH of the solutionw as then varied over the range of 6t o7 .4 to exploret he release behavior.T he photoluminescence (PL) of ICG-CD at l = 360 nm shows as pecific enhancement in the pH 6s olutiond epending on the reaction time. In addition, changes in the PL profile at a fixed normalp Ha nd at various GSH concentrationsw ere also investigated,a nd the intensities were higher than those found for only acid treatment, which implies that loaded ICG domi-nantly interacts with the hydrophobic disulfide rather than the ionic complex with cationic bPEI.…”

“…Moreover, in the narrow scan of S2p, the signal corresponding to the SÀSb ond in ICG-CD at 164.2 eV is attenuated after GSH treatment, whereas as harp SÀHs ignal (163.1 eV) appears that corresponds to cleavage of the disulfide (SÀS) bonds induced by the reductive activity of GSH on the thiol bonds. [29] Additionally,t he peak for SO 3À at 168.2 eV is found in the ICG-CD samples;h owever,a cid and redox treatments cause ad ecrease in this peak, as ICG is released from the FA-CD system.A saresult,t he ICG-CD demonstrates clear and immediate pH/redox-controllable ICG release in response to GSH and low pH values through completeb reakage of the disulfidec ross-linked sites of the CD core and ionic complex. Owing to hydrophobicity at the cross-linked sites on the FA-CD core, ICG can assemble in theses ites by simple physical mixing for 24 h. What is more,I CG can be partially ionically complexed with cationic bPEI in the CD system,w hich results in the simultaneous deposition of ICG in the shell and core.…”

“…The existence of ICG inside the FA‐CD system is also revealed by the N 1s spectrum, which shows a peak at a binding energy of 399.8 eV for an ionic complex between ICG and cationic bPEI. Moreover, in the narrow scan of S 2p, the signal corresponding to the S−S bond in ICG‐CD at 164.2 eV is attenuated after GSH treatment, whereas a sharp S−H signal (163.1 eV) appears that corresponds to cleavage of the disulfide (S−S) bonds induced by the reductive activity of GSH on the thiol bonds . Additionally, the peak for SO 3− at 168.2 eV is found in the ICG‐CD samples; however, acid and redox treatments cause a decrease in this peak, as ICG is released from the FA‐CD system.…”

Carbon Quantum Dots: A Component of Efficient Visible Light Photocatalysts

“…Pulsed laser irradiation of toluene [17], hydrothermal treatment of citric acid [18], electrochemical carbonization of low-molecular-weight alcohols [19] and microwave-assisted pyrolysis of citric acid formamide solution [20] have already been utilized for the preparation of CQDs. Recently, biomass molecules, such as sucrose [21], glucose [22], cellulose [23] and amino acid [24], have attracted great attentions as suitable precursors for the preparation of CQDs via dehydrate and further carbonize. Moreover, raw biomass is also suitable precursor for the preparation of CQDs, as a strategy potential for large-scale production.…”