A facile “off–on” fluorescence sensor for pentachlorophenol detection based on natural N and S co-doped carbon dots from crawfish shells

An overview on animal/human biomass-derived carbon dots for optical sensing and bioimaging applications

“…The elemental analysis (EA) of N-CDs derived from dried shrimp by energy dispersive X-ray (EDX) spectroscopy showed the presence of 23.57 wt% of N atoms together with other elemental (S: 6.22 wt% and P: 0.32 wt%) peaks, and therefore the fairly high QY is attributed to the synergistic role of other elements together with the high N content for excellent fluorescence properties. 177 A high absolute QY of 50.2% 185 and good relative QY of 18.57% 186 for N,S-CDs recently derived from crayfish shell using the HT method were also remarkable.…”

“…172 This unique phenomenon was explained by the generation of ˙OH radicals, which effectively destroyed the surface emissive centers in N-CDs (responsible for their emission) rather than the nuclear states (mainly cause absorption). The recently reported doped CDs from crayfish shell, 186,187 milk powder, 200 fish scales, 231 and fish scale collagen peptides 234 also showed excellent photo-stability. The photo-stability of animal/human biomass-derived CDs was also demonstrated for different period of times in air 134,150,172,174,183,247 and even after storage for many days/months/year under ambient conditions.…”

Natural Nitrogen-Doped Carbon Dots Obtained from Hydrothermal Carbonization of Chebulic Myrobalan and Their Sensing Ability toward Heavy Metal Ions

“…The stretching vibration of minor C–H peaks at 2952 cm −1 in the ATR-FTIR spectrum of the NN-CDs specified that the NN-CDs were composed of few hydrocarbons. On the other hand, the ATR-FTIR spectrum of the NN-CDs had significant peaks at 1701, 1600, 1475, 1312, 1195, and 1090–960 cm −1 corresponding with the C=O stretching, C=C stretching, C–N stretching, O–H bending, C–OH stretching, and C–O–C stretching modes [ 45 , 46 ]. The peak at 770 cm −1 could be ascribed to the out-plane –CH 2 stretching and N–H bending vibrations of the aromatic carbon structure [ 47 ].…”

Colorimetric and fluorometric dual-mode determination of hypochlorite based on redox-mediated quenching

“…HRTEM (inset) reveals that the N, S@g-CDs exhibit high degree of crystallinity with a lattice spacing of 0.20 nm, affirming the (002) lattice fringes of graphene. 32 The average particle size of N, S@g-CDs was found to be 3.4 nm ± 0.25 nm (Fig. 1B).…”