title: Protein-based electrochemical biosensor for detection of silver(I) ions.
abstract: Silver(I) ions are extremely toxic to aquatic animals. Hence, monitoring of these ions in the environment is needed. The aim of the present study was to suggest a simple biosensor for silver(I) ions detection. The suggested biosensor is based on the modification of a hanging mercury drop electrode (HMDE) by the heavy metal binding protein metallothionein (MT) for silver(I) ions detection. Metallothionein accumulated for 120 s onto the HMDE surface. After rinsing the electrode, the biosensor (MT modified HMDE) was prepared prior to detection of silver(I) ions. The biosensor was immersed in a solution containing silver(I) ions. These ions were bound to the MT structure. Furthermore, the electrode was rinsed and transferred to a pure supporting electrolyte solution, in which no interference was present. Under these experimental conditions, other signals relating to heavy metals naturally occurring in MT were not detected. This phenomenon confirms the strong affinity of silver(I) ions for MT. The suggested biosensor responded well to higher silver(I) ion concentrations. The relative standard deviation for measurements of concentrations higher than 50 microM was approximately 2% (n = 8). In the case of concentrations lower than 10 microM, the relative standard deviation increased to 10% (n = 8). The detection limit (3 signal/noise) for silver(I) ions was estimated as 500 nM.
authors.affiliation: Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, Brno, Czech Republic.
authors.forename: Sona
authors.initials: S
authors.lastname: Krizkova
authors.forename: Dalibor
authors.initials: D
authors.lastname: Huska
authors.forename: Miroslava
authors.initials: M
authors.lastname: Beklova
authors.forename: Jaromir
authors.initials: J
authors.lastname: Hubalek
authors.forename: Vojtech
authors.initials: V
authors.lastname: Adam
authors.forename: Libuse
authors.initials: L
authors.lastname: Trnkova
authors.forename: Rene
authors.initials: R
authors.lastname: Kizek
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D004563:Electrochemistry; D008668:Metallothionein / Q000737:chemistry*; D011817:Rabbits; D012834:Silver / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D012834:Silver; D008668:Metallothionein