title: β-Cyclodextrin functionalised gold nanoclusters as luminescence probes for the ultrasensitive detection of dopamine.
abstract: A novel luminescence probe based on mono-6-amino-β-cyclodextrin (NH2-β-CD) functionalised gold nanoclusters (β-CD-AuNC) was designed for dopamine (DA) detection. The NH2-β-CD molecules were conjugated onto the surface of 11-mercaptoundecanoic acid capped AuNCs (11-MUA-AuNC) via a carbodiimide coupling reaction. The integrity of the β-CD cavities was preserved on the surface of AuNCs and they retained their capability for molecular DA host-guest recognition. DA could be captured by the β-CD cavities to form an inclusion complex in which the oxidised DA could quench the fluorescence of the β-CD-AuNC probe by electron transfer. The probe could be used to quantify DA in the range of 5-1000 nM with a detection limit of 2 nM. This sensitivity was 1-2 orders of magnitude higher than that in previously reported methods. Interference by both ascorbic acid (AA) and uric acid (UA) was not observed. Therefore, the β-CD-AuNC probe could be directly used to determine the DA content in biological samples without further separation. This strategy was successfully applied to a DA assay in spiked human serum samples and it exhibited remarkable accuracy, sensitivity and selectivity.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China. jrzhang@nju.edu.cn jjzhu@nju.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Ban
authors.forename: E S
authors.initials: ES
authors.lastname: Abdel-Halim
authors.forename: Jianrong
authors.initials: J
authors.lastname: Zhang
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Zhu
mesh_terms: D004298:Dopamine / Q000097:blood*; D015259:Dopamine Agents / Q000097:blood*; D005227:Fatty Acids / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D049449:Luminescence; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D013438:Sulfhydryl Compounds / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: C505222:11-mercaptoundecanoic acid; D015259:Dopamine Agents; D005227:Fatty Acids; D049408:Luminescent Agents; D013438:Sulfhydryl Compounds; D047392:beta-Cyclodextrins; D006046:Gold; C031215:betadex; D004298:Dopamine