title: A rapid microwave synthesis of nitrogen-sulfur co-doped carbon nanodots as highly sensitive and selective fluorescence probes for ascorbic acid.
abstract: A ultrafast one-step microwave-assisted method was developed for the synthesis of nitrogen-sulfur co-doped carbon nanodots (N,S-CDs) by using ethylenediamine as the carbon source and sulfamic acid as the surface passivation reagent. The morphology and the properties of N,S-CDs were explored by a series of techniques, such as high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis absorption and fluorescence spectroscopy. The prepared N,S-CDs exhibit bright blue photoluminescence with a high fluorescence quantum yield (FLQY) up to 28%, and high stability and excellent water solubility. A N,S-CDs-based fluorescent probe was developed for sensitive detection ascorbic acid (AA) in the presence of Cu(2+), based on the mechanism that AA reduces Cu(2+) to Cu(+), then Cu(+) quenches the fluorescence of N,S-CDs through electron or energy transfer due to the interaction between Cu(+) and thiol ligand on the N,S-CDs surface. The observed linear response concentration range was from 0.057 to 4.0μM to AA with a detection limit as low as 18nM. The probe exhibited a highly selective response toward AA even in the presence of possible interfering substances, such as uric acid and citric acid. Moreover, these promising features made the sensing system used for the analysis of human serum and urine samples.
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China.
authors.forename: Junxia
authors.initials: J
authors.lastname: Duan
authors.affiliation: Department of Chemistry, Xinxiang Medical University, Xinxiang 453007, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yu
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China. Electronic address: slfeng@htu.edu.cn.
authors.forename: Suling
authors.initials: S
authors.lastname: Feng
authors.affiliation: School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, China.
authors.forename: Li
authors.initials: L
authors.lastname: Su
mesh_terms: D001205:Ascorbic Acid; D002244:Carbon; D006801:Humans; D008872:Microwaves; D049329:Nanostructures; D009584:Nitrogen; D013455:Sulfur
chemical_list: D013455:Sulfur; D002244:Carbon; D009584:Nitrogen; D001205:Ascorbic Acid
keywords: Ascorbic acid; Fluorescence probe; Microwave; Nitrogen–sulfur co-doped carbon dots