Carbon dots from tryptophan doped glucose for peroxynitrite sensing

Abstract

Tryptophan doped carbon dots (Trp-CD) were microwave synthesized. The optimum conditions of synthesizing of the Trp-CD were established by response surface multivariate optimization methodologies and were the following: 2.5 g of glucose and 300 mg of tryptophan diluted in 15 mL of water exposed for 5 min to a microwave radiation of 700 W. Trp-CD have an average size of 20 nm, were fluorescent with a quantum yield of 12.4% and the presence of peroxynitrite anion (ONOO(-)) provokes quenching of the fluorescence. The evaluated analytical methodology for ONOO(-) detection shows a linear response range from 5 to 25 μM with a limit of detection of 1.5 μM and quantification of 4.9 μM. The capability of the ONOO(-) quantification was evaluated in standard solutions and in fortified serum samples.

Peroxynitrite and nitric oxide fluorescence sensing by ethylenediamine doped carbon dots

“…The LOD found is generally higher than the obtained by other electrochemical sensors [20,21]. Nevertheless, and in comparison to the obtained by almost all of the already developed NO and ONOO − fluorescence nanoparticles optical sensors, a comparable LOD was observed [22][23][24][25][26][27][28][29][30]. Generally good quantifications results were found for the two RNS in the assays with the standard solutions and fortified serum samples.…”

“…Due to their role, the analytical methodologies for their detection and/or quantification, based in different analytical methodologies, are of great relevance [20,21]. Fluorescent detection of ONOO − by nanoparticles was done by quenching methods based in thiol-capped CdTe or CdTe/ZnS quantum dots (QD) [22] and in tryptophan doped CDs [23]. Fluorescent detection of NO by nanoparticles was also done by some quenching methods based in carboxymethyl chitosan CdTe [24], in chitosan CdSe [25,26], in polymethacrylate CdSe/ZnS [27] and in triethanolamine CdSe QDs [28], by a turn on method based in iron(III) dithiocarbamates CdSe/ZnS QDs [29] and by a fluorescence resonance energy transfer (FRET) ratiometric method based in phenylenediamine-containing naphthalimide functionalized CDs synthesized from CA and EDA [30].…”

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

“…For example in 2014, Leitão et al described the microwave synthesis of CDs using 2.5 g of glucose and 0.3 g of tryptophan as the N-dopant/surface passivation agent (Scheme 5) [33]. The resultant CDs had a QY of up to 12% (34-times higher than that of the undoped CDs).…”

Highly luminescent S,N co‐doped carbon quantum dots‐sensitized chemiluminescence on luminol–H2O2 system for the determination of ranitidine

“…Fluorescent carbon quantum dots (CQDs) have attracted much attention due to their unique properties and wide range of applications in chemiluminescence (CL), bioimaging, fluorescence quenching and photocatalysis . CQDs appear to be almost spherical, generally with a size of < 10 nm, and are a zero‐dimensional carbon nano‐material .…”