One-step synthesis of biofunctional carbon quantum dots for bacterial labeling

One-step, green, and economic synthesis of water-soluble photoluminescent carbon dots by hydrothermal treatment of wheat straw, and their bio-applications in labeling, imaging, and sensing

“…Intracellular sensing techniques for different analytes develop rapidly. In addition to sensing ions by the naked C-dots, C-dots modified with specific recognizing ligands can be also used to sensing or detecting larger molecules such as hydrogen sulfide [23] , blood sugar [57] , dopamine [58] , and even cells in aqueous solutions [59][60] , which still benefits their active surface moieties for chemical conjugations. In the recent published work of Weng C. et al, they attained a detection limit of 10 -3 CFU mL -1 of E. coli in tap water, apple juice and human urine with their mannose modified C-dots [59] .…”

“…In addition to sensing ions by the naked C-dots, C-dots modified with specific recognizing ligands can be also used to sensing or detecting larger molecules such as hydrogen sulfide [23] , blood sugar [57] , dopamine [58] , and even cells in aqueous solutions [59][60] , which still benefits their active surface moieties for chemical conjugations. In the recent published work of Weng C. et al, they attained a detection limit of 10 -3 CFU mL -1 of E. coli in tap water, apple juice and human urine with their mannose modified C-dots [59] . Very recently, Wang's group developed a Förster resonance energy transfer (FRET)-based method for detecting two kinds of pathogenic bacteria, in which they used green and red semiconductor Q-dots modified with the aptamers for recognizing bacteria as the FRET donors and the C-dots as the acceptor [60] .…”

Green synthesis of fluorescent carbon dots from carrot juice for in vitro cellular imaging

“…By contrast, the hydrothermal method is considered to be a facile, green, and efficient approach. Recently, natural biomass precursors as raw materials (such as glucose, konjac, chitosan, potato, Prunus mume fruit, cabbage, egg, grass, coffee, and others) for the preparation of functional CDs via the hydrothermal method have gained popularity due to the abundance of these carbon sources, as well as their availability, low cost, and eco-friendliness [14,[20][21][22][23][24][25][26][27][28]. In this regard, the preparation of high quality CDs from a suitable biomass as a carbon source is essential.…”

Carbon “Quantum” Dots for Fluorescence Labeling of Cells

“…Among more significant recent successes have been the finding and subsequent development of carbon "quantum" dots or more appropriately called carbon dots (for the lack of the classical quantum confinement effect in these nanomaterials), [4][5][6][7][8][9][10][11] which have played a leading role in an emerging and rapidly -3 -expanding research field centered on the design, preparation, and potential biomedical uses of various carbon-based QDs. [12][13][14][15][16][17][18][19][20][21][22][23][24][25] Carbon dots are generally small carbon nanoparticles with various surface passivation schemes by organic or bio-molecules (Figure 1), 4,6,7,12 where the more effective surface passivation has been correlated with brighter fluorescence emissions from the corresponding dots. The optical absorption of carbon dots is assigned to π-plasmon transitions in the carbon nanoparticle core of the dots, while the fluorescence emissions in the visible to near-IR are attributed to photogenerated electrons and holes trapped at diverse surface sites and their associated radiative recombinations.…”