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Protein‐based electrochemical biosensor for detection of silver(I) ions
Author(s) -
Krizkova Sona,
Huska Dalibor,
Beklova Miroslava,
Hubalek Jaromir,
Adam Vojtech,
Trnkova Libuse,
Kizek Rene
Publication year - 2010
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.77
Subject(s) - biosensor , chemistry , detection limit , metal ions in aqueous solution , ion , analytical chemistry (journal) , metallothionein , metal , inorganic chemistry , chromatography , cadmium , biochemistry , organic chemistry
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 µM was approximately 2% ( n = 8). In the case of concentrations lower than 10 µM, the relative standard deviation increased to 10% ( n = 8). The detection limit (3 signal/noise) for silver(I) ions was estimated as 500 nM. Environ. Toxicol. Chem. 2010;29:492–496. © 2009 SETAC