title: Sulfur-doped graphene quantum dots as a novel fluorescent probe for highly selective and sensitive detection of Fe(3+).
abstract: Sulfur-doped graphene quantum dots (S-GQDs) with stable blue-green fluorescence were synthesized by one-step electrolysis of graphite in sodium p-toluenesulfonate aqueous solution. Compared with GQDs, the S-GQDs drastically improved the electronic properties and surface chemical reactivities, which exhibited a sensitive response to Fe(3+). Therefore, the S-GQDs were used as an efficient fluorescent probe for highly selective detection of Fe(3+). Upon increasing of Fe(3+) concentration ranging from 0.01 to 0.70 μM, the fluorescence intensity of S-GQDs gradually decreased and reached a plateau at 0.90 μM. The difference in the fluorescence intensity of S-GQDs before and after adding Fe(3+) was proportional to the concentration of Fe(3+), and the calibration curve displayed linear regions over the range of 0-0.70 μM. The detection limit was 4.2 nM. Finally, this novel fluorescent probe was successfully applied to the direct analysis of Fe(3+) in human serum, which presents potential applications in clinical diagnosis and may open a new way to the design of effective fluorescence probes for other biologically related targets.
authors.affiliation: Department of Chemistry, Beijing Normal University , Beijing 100875, People's Republic of China.
authors.forename: Shuhua
authors.initials: S
authors.lastname: Li
authors.forename: Yunchao
authors.initials: Y
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Cao
authors.forename: Jia
authors.initials: J
authors.lastname: Zhu
authors.forename: Louzhen
authors.initials: L
authors.lastname: Fan
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Li
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D057230:Limit of Detection; D045663:Quantum Dots; D013455:Sulfur / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D014867:Water; D013455:Sulfur; D006108:Graphite; D007501:Iron