An Aqueous Route to Multicolor Photoluminescent Carbon Dots Using Silica Spheres as Carriers

Abstract

Carbon lights up: A facile chemical method yields multicolor photoluminescent carbon dots derived from polymer/silica nanocomposites, which were prepared using surfactant-modified silica spheres as carriers and resols (phenol/formaldehyde resins) as carbon precursor (see picture). The surface-passivated carbon dots show good biocompatibility as potential bioimaging agents offering nanometer-scale resolution.

Enhanced photoluminescence and characterization of multicolor carbon dots using plant soot as a carbon source

“…Among them, carbon dots are a new class of functional nanomaterials exhibiting their inherently unique photoluminescent properties, such as wavelengthtuneable emission, excellent solubility, good biocompatibility and chemical inertion [7][8][9][10]. Unlike the semiconductor quantum dots derived from heavy metal precursors incurring long term toxicity [11], C-dots are environmentally friendly and lack of known cytotoxicity [12,13].…”

“…In order to enhance the quantum yield (QY) of carbon dots, much effort has been directed toward the use of surface passivation method to achieve a strong photoluminescence [13]. Doping C-dots with inorganic salt ZnS or SiO 2 is able to enhance the QY of C-dots [10]. Enhancing the luminescence of C-dots with a reduction pathway is also reported recently [18].…”

Effect of the Elemental Composition of Precursors from Amino Acids and Their Binary Mixtures on the Photoluminescent Intensity of Carbon Nanodots

“…16 CNDs have been mainly prepared by oxidative procedures for the treatment of various carbon sources, such as graphite, 17 candle soot, 18 and organic compounds. 19 Several synthetic approaches 20 were applied to tune the PL properties of CNDs by a post-treatment, such as chemical reduction, 21 organosilane-functionalization, 22 and electrochemical agitation. 23 Among them, hydrothermal 24 and microwaveassisted 25 treatments of organic precursors, natural products 26 and raw materials 27 have been widely used to prepare CNDs.…”

Improved Fluorescence of Carbon Dots Prepared from Bagasse under Alkaline Hydrothermal Conditions

“…Many researchers have developed a variety of synthetic methods to prepare environmentfriendly CDs, including laser irradiation of graphite (Sun et al 2006;Hu et al 2009), electrochemical oxidation of graphite (Zhao et al 2008;Zheng et al 2009), multi-walled carbon nanotubes (Zhou et al 2007), neutron beam radiation of nano-diamond (Yu et al 2005;Fu et al 2007), chemical oxidation (Liu et al 2007;Tian et al 2009;Peng and Travas-Sejdic 2009;Liu et al 2009;Ray et al 2009;Zhang et al 2010;Pan et al 2010;), hydrothermal oxidation (Bourlinos et al 2008) of the appropriate precursors, and microwave decomposition of carbohydrates (Zhu et al 2009). …”

“…Typically, nitric acid oxidative treatment has been used to introduce carbonyl functionalities at the surfaces (Liu et al 2007;Tian et al 2009;Dong et al 2010), and different surface passivate agents, primarily amino-terminated reagents, have been then used for the surface passivation of CDs through the formation of amide linkages (Peng et al 2009;Liu et al 2009). These methods can improve the quantum yields about 10-fold.…”