title: A carbon dot-based "off-on" fluorescent probe for highly selective and sensitive detection of phytic acid.
abstract: We herein report a facile, one-step pyrolysis synthesis of photoluminescent carbon dots (CDs) using citric acid as the carbon source and lysine as the surface passivation reagent. The as-prepared CDs show narrow size distribution, excellent blue fluorescence and good photo-stability and water dispersivity. The fluorescence of the CDs was found to be effectively quenched by ferric (Fe(III)) ions with high selectivity via a photo-induced electron transfer (PET) process. Upon addition of phytic acid (PA) to the CDs/Fe(III) complex dispersion, the fluorescence of the CDs was significantly recovered, arising from the release of Fe(III) ions from the CDs/Fe(III) complex because PA has a higher affinity for Fe(III) ions compared to CDs. Furthermore, we developed an "off-on" fluorescence assay method for the detection of phytic acid using CDs/Fe(III) as a fluorescent probe. This probe enables the selective detection of PA with a linear range of 0.68-18.69 μM and a limit of detection (signal-to-noise ratio is 3) of 0.36 μM. The assay method demonstrates high selectivity, repeatability, stability and recovery ratio in the detection of the standard and real PA samples. We believe that the facile operation, low-cost, high sensitivity and selectivity render this CD-based "off-on" fluorescent probe an ideal sensing platform for the detection of PA.
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
authors.forename: Libing
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China. Electronic address: surx@tju.edu.cn.
authors.forename: Rongxin
authors.initials: R
authors.lastname: Su
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China. Electronic address: tjuhrl@tju.edu.cn.
authors.forename: Renliang
authors.initials: R
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: He
mesh_terms: D002244:Carbon / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis*; D008422:Materials Testing; D010833:Phytic Acid / Q000032:analysis*; D045663:Quantum Dots; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D005456:Fluorescent Dyes; D002244:Carbon; D010833:Phytic Acid
keywords: Carbon dot; Fluorescence; Off–on; Phytic acid; Sensor