Blue photoluminescent carbon nanodots from limeade

Graphene-Based Materials for Biosensors: A Review

“…The dots are obtained due to the size reduction of basal-plane carbon structures to a few nanometers approaching that of the dots with quantum phenomena. More importantly, the new materials are less toxic and are compatible for cellular internalization as verified by many groups [ 17 , 24 , 90 , 91 , 92 ].…”

“…The GQDs can be made up of a single atom of graphite layer or graphene chopped into fragments in a range of 2–20 nm. The disk feature of GQDs is very tiny, analogous to the dot [ 24 , 95 ]. Upon either stimulus by UV light or electrical energy, the excitons would be confined to the quantized energy levels and release photoluminescent light in a narrow band.…”

“…The nano- to micro-sized fragments of GO from hydrothermal cutting were passivated by placing -C=O, -OH and -COOH groups on the surface [ 96 ]. Suvarnaphaet [ 24 ] achieved high quantum yield of the GO-like structure from limeade and applied it for rapid sensing of heavy-metal ions, for bioimaging, and it was tested for biocompatibility and found to be non-toxic to human kidney cells. Dong [ 97 ] also found nano-sized GO−like structures synthesized from humic substances in the presence of nitrogen-containing groups such as -NH 2 and C=N on the surface of the carbon-based dots causing an enhancement in quantum yield.…”

“…For more precision, the presence of chemical binding or biological specificity to an analyte in a labeled technique is used to ensure that only the labeled biological activities give a strong signal. However, this technique requires a labeling process in preparation and involves the fluorescent dyes, chemiluminescent molecules, photoluminescent nanoparticles and quantum dots [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Alternatively, the label-free technique uses molecular, physical, mechanical, electrical, optical properties and charge interaction to monitor binding activities.…”

Natural‐Product‐Derived Carbon Dots: From Natural Products to Functional Materials

“…[18,19] CDs also have outstanding electronic properties as electron donors and acceptors, which endow them with wide potentialinc atalysis and optronics. [20][21][22][23][24][25][26][27][28][29] The raw carbon sources for CDs can be either man-made [e.g.,c andle soot, [30] graphite, [31] fullerene-C 60 , [32] ammonium citrate, [33] glucose and ammonium hydroxide, [34] and branched poly(ethylenimine) [35] and ethylenediamine] [36] or natural products (e.g.,o range juice, [37] milk, [38] coffee grounds, [39] Bombyxm ori silk, [40] green tea, [41] egg, [42] eggshellm embrane, [43] soy milk, [44] flour, [45] banana, [46,47] potato, [48] Punica gianatum, [49] lotus root, [50] pepper, [51] honey, [52] coriander leaves, [53] garlic, [54] Jinhua bergamot, [55] aloe, [56] rose flowers, [57] limeade, [58] hair, [59][60][61] and rice husks). [62] Most pu...…”