title: Enhanced fluorescence of chitosan based on size change of micelles and application to directly selective detecting Fe³⁺ in human serum.
abstract: In this paper, we have developed an approach to significantly enhance fluorescence of chitosan by simply heated the inherently low fluorescent chitosan aqueous solution. Enhanced blue fluorescence of chitosan solution was observed as originated from the formation of small size of chitosan micelle after long time heated. The fluorescence of chitosan micelles was quenched and recovered when Fe³⁺ ions were combined and released from chitosan micelles. Therefore, chitosan without modification of functional groups can recognize Fe³⁺ with very high selectivity. As a result, a new fluorescence sensor for sensitively detecting Fe³⁺ ion based on the change of chitosan micelles sizes was subsequently fabricated. This enhanced fluorescence enables the chitosan sensor to be sensitive to low concentrations of Fe³⁺, and it is linear responsive in the range of 1.96×10⁻⁸ to 2.00×10⁻⁵ M. Importantly, this novel sensor may be applied in human serum for direct detection of Fe³⁺ ion without sample pretreatment. Analysis of 5 samples of human serum shows that the average concentration of Fe³⁺ is 26.95 μM, which is consistent with the results determined by other methods. Moreover, the advantage of chitosan-based assay is that Fe³⁺ rather than Fe²⁺ in human serum can be directly measured, avoiding costly, time-consuming and complex process.
authors.affiliation: Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education. School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, PR China. hhwn@iccas.ac.cn
authors.forename: Haowen
authors.initials: H
authors.lastname: Huang
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Shenna
authors.initials: S
authors.lastname: Chen
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.forename: Bo
authors.initials: B
authors.lastname: Liao
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Long
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Zeng
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xia
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D005453:Fluorescence; D006801:Humans; D007477:Ions / Q000097:blood / Q000302:isolation & purification*; D007501:Iron / Q000097:blood / Q000302:isolation & purification*; D008823:Micelles; D010316:Particle Size; D012996:Solutions
chemical_list: D007477:Ions; D008823:Micelles; D012996:Solutions; D048271:Chitosan; D007501:Iron