“Light on” fluorescence carbon dots with intramolecular hydrogen bond-regulated co-planarization for cell imaging and temperature sensing

Abstract

Turn-on thermosensitive carbon dots (CDs) with dual function of imaging and sensing are desirable for biological research and clinical diagnosis at cellular level. Herein, we synthesized eight types of novel...

From Small Molecules to Zero-Dimensional Carbon Nanodots: Chasing the Stepwise Transformations During Carbonization

“…Also, deconvoluted peaks around 286.2, 287.9, and 288.8 eV correspond to the −C−N/C−(C−OH), C−N/C− O, and C�O groups, respectively. 9,13,25,41 On the other hand, the high-resolution N 1s spectra deconvoluted into two prominent peaks corresponding to various N species. A peak around 399.8 eV suggests the presence of pyridinic nitrogen atoms, and a peak around 401.3 eV corresponds to the −NH 2 / NH 3 + species.…”

“…), we can also unveil the stepwise transformation of N-CDs. To be very specific, the temperature can indirectly affect the matrix rigidity/flexibility of the surrounding environment of the chromophoric species, which eventually affects the PL properties of CDs. ,,− Accordingly, we have studied thermo-responsive PL properties of the as-synthesized N-CDs at various reaction times, and the same has been depicted in Figure . Figure a shows the PL intensities of the N-CDs (prepared at various reaction times: 30, 120, 240, and 480 min) as a function of temperature from 15 to 80 °C (heating process) and 80 to 15 °C (cooling process).…”

“…A prominent peak around 284.7 eV corresponds to the sp 3 -hybridized (−C–C) carbon. Also, deconvoluted peaks around 286.2, 287.9, and 288.8 eV correspond to the −C–N/C–(C–OH), C–N/C–O, and CO groups, respectively. ,,, On the other hand, the high-resolution N 1s spectra deconvoluted into two prominent peaks corresponding to various N species. A peak around 399.8 eV suggests the presence of pyridinic nitrogen atoms, and a peak around 401.3 eV corresponds to the −NH 2 /NH 3 + species. ,, In the case of N-CDs at 120 min reaction time, the C 1s spectra deconvoluted into four peaks.…”

Light-nutrition coupling effect of degradable fluorescent carbon dots on lettuce

“…1d and e, the peak at 300-400 nm is attributed to the surface state (CO in the aromatic ring) n → π* transition, while the peak below 300 nm is assigned to the π → π* transition of the CC bond. 28,29 The decreasing absorbance indicates the remarkable chemical structure transformation. Though the supplementation of UV-A light exacerbates the fluorescence quenching phenomenon, it does not significantly shorten the PL lifetime compared with that under LED light (Fig.…”

Natural deep eutectic solvent assisted synthesis and applications of chiral carbon dots

“…In addition, as the intramolecular hydrogen interaction can significantly increase the energy gap between ππ* and nπ* states and reduce the non-radiative relaxation of the excited state, the increase in the fluorescence intensity and fluorescence lifetime may be caused by the intramolecular hydrogen bonds and the proximity of hydrogen bonds. [39][40][41] Amino acid enantiomers with different configurations have different physical and chemical properties and may act differently with CCDs (Fig. S12 †).…”