title: Thermoresponsive magnetic nano-biosensors for rapid measurements of inorganic arsenic and cadmium.
abstract: Green fluorescent protein-tagged sensor proteins, ArsR-GFP and CadC-GFP, have been produced as biosensors for simple and low-cost quantification of As(III) or Cd(II). In this study, the sensor protein-promoter DNA complexes were reconstructed on the surfaces of magnetic particles of different sizes. After the surface modification all the particles could be attracted by magnets, and released different amounts of GFP-tagged protein, according to the metal concentrations within 5 min, which caused significant increases in fluorescence. A detection limit of 1 µg/L for As(III) and Cd(II) in purified water was obtained only with the nanoparticles exhibiting enough magnetization after heat treatment for 1 min. Therefore, thermoresponsive magnetic nano-biosensors offer great advantages of rapidity and sensitivity for the measurement of the toxic metals in drinking water.
authors.affiliation: United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu 183-8509, Japan. msrsiddiki@yahoo.com
authors.forename: Mohammad Shohel Rana
authors.initials: MS
authors.lastname: Siddiki
authors.forename: Shun
authors.initials: S
authors.lastname: Shimoaoki
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Ueda
authors.forename: Isamu
authors.initials: I
authors.lastname: Maeda
mesh_terms: D001151:Arsenic / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002104:Cadmium / Q000032:analysis*; D060766:Drinking Water / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D005427:Flocculation; D059346:Magnets / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D002104:Cadmium; D001151:Arsenic