Chemical Research in Chinese Universities ›› 2013, Vol. 29 ›› Issue (5): 845-849.doi: 10.1007/s40242-013-3180-x

• Articles • Previous Articles     Next Articles

Conjugated Polyelectrolyte-Ag+ Fluorescent Switch for Biothiol Sensing

XIAO Yi1, LI Sha1, HUANG Hong-mei1, ZHANG Ye1, XUE Zun-zun1, TANG Xue-yan1, HE Xiao-xiao2, WANG Ke-min2   

  1. 1. Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, P. R. China;
    2. State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University, Changsha 410082, P. R. China
  • Received:2013-04-22 Revised:2013-06-04 Online:2013-10-01 Published:2013-09-17
  • Contact: HUANG Hong-mei, WANG Ke-min E-mail:huanghongmei@hunnu.edu.cn;kmwang@hnu.edu.cn
  • Supported by:

    Supported by the National Natural Science Foundation of China(No.20805014), the Scientific Research Fund of Hunan Provincial Education Department, China(Nos.11C0809 and 12B077), the Open Fund Project of Key Laboratory in Hunan University, China(No.201103) and the Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province, China.

Abstract:

A new "off-on" switch for sensitive and selective fluorescence detection of biothiols[glutathione(GSH), cysteine(Cys) and homocysteine(Hcy)] was developed based on an anionic conjugated polyelectrolyte(CPE), pyridyl-functionalized poly(phenylene ethynylene)(P1). The fluorescence of P1 can be significantly quenched by Ag+ due to complexation-mediated interpolymer aggregation. Furthermore, biothiols can efficiently recover the fluorescence intensity of P1 as a result of the stronger binding between thiol group and Ag+, which dissociates P1 from the P1/Ag+ complex and disrupts interpolymer aggregation. Under optimum conditions, a good linear relationship in a range of 100―4200 nmol/L is obtained for GSH with a detection limit of 80 nmol/L(S/N=3). As a result of specific interaction between the thiol group and Ag+, the proposed method shows a high selectivity for biothiols. In addition, the CPE-based fluorescence "off-on" switch has been used to quantitatively detect total biothiols in cell lysates.

Key words: Fluorescent switch, Biothiol, Silver(I), Conjugated polyelectrolyte