Label-free colorimetric assay for biological thiols based on ssDNA/silver nanoparticle system by salt amplification

被引：35

作者：

Chen, Zhang ^{[1
]}

He, Yejuan ^{[1
]}

Luo, Shenglian ^{[1
,2
]}

Lin, Hailan ^{[1
]}

Chen, Yufang ^{[1
]}

Sheng, Pengtao ^{[1
]}

Li, Juanxiu ^{[1
]}

Chen, Beibei ^{[1
]}

Liu, Chengbin ^{[1
]}

Cai, Qinyun ^{[1
]}

机构：

[1] Hunan Univ, Dept Chem, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Hunan, Peoples R China

[2] Nanchang Hangkong Univ, Sch Environm & Chem Engn, Nanchang 330063, Peoples R China

来源：

ANALYST | 2010年 / 135卷 / 05期

基金：

中国国家自然科学基金; 美国国家科学基金会;

关键词：

GOLD NANOPARTICLES; SELECTIVE DETECTION; AMINO-ACIDS; CYSTEINE; HOMOCYSTEINE; GLUTATHIONE; MECHANISM; SILVER; RECOGNITION; MOLECULES;

D O I：

10.1039/b925683k

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

We report a novel method for biological thiols detection using ssDNA/sliver nanoparticles system. The adsorbing ssDNA supplies silver nanoparticles high density charge to rescue nanoparticles from aggregation induced by salt. However, homocysteine (cysteine or glutathione) is conjugated more powerfully than ssDNA to AgNPs via Ag-S bond, which holds back ssDNA binding to AgNPs surface. When salt is added, AgNPs aggregation occurs and the corresponding color changes from yellow to brown after these biological thiols is introduced. A high sensitivity can be achieved using salt as an amplifier to assay thiols. In our study, a favorable linear correlation between the A(0)/A(x) ratio and homocysteine concentration was obtained in the range of 10 to 500 nM with a low detection limit of 10 nM, indicating that homocysteine could be analyzed at low concentration. A concentration as low as 300 nM homocysteine caused a visible color change. As well as, cysteine and glutathione can be detected at a detection limit of 50 nM and 100 nM, respectively. In addition, study on the selectivity of this method shows that only homocysteine, cysteine and glutathione can generate signal response.

引用

页码：1066 / 1069

页数：4

共 28 条

[11] Homocysteine-mediated reactivity and assembly of gold nanoparticles [J].