One-step synthesis of fluorescent hydroxyls-coated carbon dots with hydrothermal reaction and its application to optical sensing of metal ions

Abstract

Carbon dots (CDs) with average diameter of 3.1 ± 0.5 nm were facilely synthesized with candle soot through hydrothermal reaction in sodium hydroxide aqueous solution. The as-prepared CDs were covered with a lot of hydroxyls, possessed properties of good water-solubility, anti-photobleaching, salt tolerance, and low cytotoxicity, and had a fluorescence quantum yield (QY) of about 5.5%. The fluorescence of the hydroxyls-coated CDs could be selectively quenched by metal ions such as Cr 3+ , Al 3+ and Fe 3+ , which is because these metals can easily combine with the hydroxyl groups on the surface of CDs and induce aggregation of hydroxyls-coated CDs. Experiments showed that the quenching of Cr 3+ had a Sterm-Volmer constant of 1.03 × 10 7 M -1 with a liner range of 1.0-25.0 μM and detection limit of 60 nM (3σ). carbon dots, fluorescence, quantum yield, cytotoxicity, metal ions

Selective and sensitive chemosensor for lead ions using fluorescent carbon dots prepared from chocolate by one-step hydrothermal method

“…The peaks at 1584 cm −1 and 1090 cm −1 indicated the existence of C=C and C-O, respectively. While the peak centered at 2948 cm −1 was ascribed to the stretching vibrations of C-H [38]. It is found that the as-prepared CDs are surrounded by -OH groups which make the obtained CDs not only display excellent water solubility but also easily coordinate with some metal ions [39].…”

A sustainable alternative to synthesis optical sensing receptor for the detection of metal ions

“…5). This could lead to the deprotonation at the surface of the CNPs and can subsequently weaken the intermolecular hydrogen bonds that initially attracting the CNPs together [33]. Aggregation often causes self-quenching to take place and will turn off the fluorescence.…”

Synthesis of carbon nanoparticles using one step green approach and their application as mercuric ion sensor

“…It is reported that the optical, physical and chemical properties of produced CNPs are influenced by the molecular precursors used, methodology and the pre-treatment performed. Apart from optical sensing CNPs have found widespread applications in the areas of bioimaging [18,19], photocatalysis [20], optoelectronics [21], etc.…”