solid phase biosensors for arsenic or cadmium composed of a trans factor and cis element complex固相生物传感器对砷和镉反式因子和独联体元素组成的复杂.pdf

Sensors 2011, 11, 10063-10073; doi:10.3390/s111110063 OPEN ACCESS sensors ISSN 1424-8220 /journal/sensors Article Solid Phase Biosensors for Arsenic or Cadmium Composed of A trans Factor and cis Element Complex Mohammad Shohel Rana Siddiki 1, Yasunari Kawakami 2, Shunsaku Ueda 1,2 and Isamu Maeda 1,2,* 1 United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu 183-8509, Japan; E-Mails: msrsiddiki@ (M.S.R.S.); uedashun@cc.utsunomiya-u.ac.jp (S.U.) 2 Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya 321-8505, Japan; E-Mail: kaaaaa25@yahoo.co.jp (Y.K.) * Author to whom correspondence should be addressed; E-Mail: i-maeda@cc.utsunomiya-u.ac.jp; Tel.: +81-28-649-5477; Fax: +81-28-649-5477. Received: 16 September 2011; in revised form: 18 October 2011 / Accepted: 24 October 2011 / Published: 25 October 2011 Abstract: The presence of toxic metals in drinking water has hazardous effects on human health. This study was conducted to develop GFP-based-metal-binding biosensors for on-site assay of toxic metal ions. GFP-tagged ArsR and CadC proteins bound to a cis element, and lost the capability of binding to it in their As- and Cd-binding conformational states, respectively. Water samples containing toxic metals were incubated on a complex of GFP-tagged ArsR or CadC and cis element which was immobilized on a solid surface. Metal concentrations were quantified