title: A colorimetric sensor for determination of cysteine by carboxymethyl cellulose-functionalized gold nanoparticles.
abstract: A simple and sensitive colorimetric method for cysteine detection was established based on the carboxymethyl cellulose-functionalized gold nanoparticles (CMC-AuNPs). The nanoparticles were directly synthesized with sodium carboxymethyl cellulose by a simple approach, which would protect particles against salt-induced aggregation. Then the CMC-AuNPs solution exhibited a high colorimetric selectivity to cysteine. The assay results indicated that the introduction of cysteine could induce the aggregation of the colloidal solutions at the presence of sodium chloride, displaying changes in color and in UV-vis absorption spectra. Thus an exceptionally simple, rapid method for detecting cysteine was obtained at the linear range of 10.0-100.0 microM with the relative coefficient of 0.997. The proposed method possessed the advantages of simplicity and sensitivity, and was applied to real urine sample detection. The results were satisfying and the proposed method was especially appropriate for detection of cysteine in biological samples.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Wei
authors.forename: Li
authors.initials: L
authors.lastname: Qi
authors.forename: Junjun
authors.initials: J
authors.lastname: Tan
authors.forename: Ruigang
authors.initials: R
authors.lastname: Liu
authors.forename: Fuyi
authors.initials: F
authors.lastname: Wang
mesh_terms: D000328:Adult; D015374:Biosensing Techniques / Q000191:economics / Q000379:methods; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry; D003124:Colorimetry / Q000379:methods; D003545:Cysteine / Q000032:analysis / Q000652:urine; D005260:Female; D006046:Gold / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods
chemical_list: D006046:Gold; D002266:Carboxymethylcellulose Sodium; D003545:Cysteine