Synthesis of a carbon-dot-based photoluminescent probe for selective and ultrasensitive detection of Hg²⁺ in water and living cells

Abstract

A nitrogen and sulphur co-doped carbon dot (NSCD) based highly selective photoluminescent probe for mercury detection has been designed. The NSCDs with a PL quantum yield of 69% are easily prepared from a single polymeric molecular precursor. The turn on-off fluorescence change upon mercury addition is attributed to the nonradiative electron transfer from the excited state to the d-orbital of the metal ion. The soft-soft acid-base interaction between the sulphur part of the NSCD and Hg(2+) makes the fluorescence probe more specific and selective towards Hg(2+) in contrast to other metal ions. The limit of detection of mercury ions is found to be 0.05 nM. Due to their high photostability, low toxicity and low detection limit, these carbon dots are demonstrated to be excellent probes for the detection of Hg(2+) in the living cell.

Fabrication of nitrogen‐ and phosphorous‐doped carbon dots by the pyrolysis method for iodide and iron(III) sensing

“…Furthermore, the high‐resolution spectrum of N1 s demonstrated the three chemical environments, as shown in Figure (c). The peak centred at 399.2 eV for pyrridinic nitrogen, 400.2 eV for pyrrolic nitrogen and 401.1 eV for N‐H bond . However, the high‐resolution scan of the P2p clearly demonstrates two chemical bonds as shown in Figure (d).…”

Crown daisy leaf waste–derived carbon dots: A simple and green fluorescent probe for copper ion

“…Here, only Cu 2+ could effectively reduce the fluorescence intensity, which could be attributed to the selective complexation interaction between Cu 2+ and carboxyl and amino groups of the N‐CDs. The special complexation interaction affected the aromatic ring structure and the nonradiative recombination of the N‐CDs and formed Cu–N‐CD complexes also made the N‐CD particles close to each other, which led to significant fluorescence quenching effects . In order to testify whether the aromatic C–N heterocycle structure and amino groups influenced the selective fluorescence sensing of Cu 2+ , the control experiment was developed to study the fluorescence responses of the prepared CDs without N atom dopants toward Cu 2+ and other metal ions.…”

Luminescent assays based on carbon dots for inorganic trace analysis

“…Although N is the most extended doping species used up to date, in the last years, some works dealing with doping species Another strategy that allows achieving high fluorescence QY lies on the introduction of two doping species. To date, some combinations have been reported, including N-S (Dong et al 2013, Mohapatra et al 2015, N-P (Barman et al 2014), N-Al (Wang et al 2015b), N-B (Barman et al 2014), and N-Mn ). Among the mentioned combinations, QYs obtained by the combinations of N-S, N-P, and N-Mn, which are 54%-73%, 70%, and 83%, respectively, must be highlighted.…”

“…Recently, Mohapatra et al (2015) developed a novel method for Hg(II) determination in water and living cells using nitrogen and sulfur co-doped CDs. Hg(II) interacts with sulfur to cause fluorescence quenching.…”