Open AccessOptical features of the fluorophore azotobactin: Applications for iron sensing in biological fluids
Author(s) -
Sharma Manisha,
Gohil Nivedita Karmakar
Publication year - 2010
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.201000038
Subject(s) - siderophore , biosensor , azotobacter vinelandii , fluorescence , fluorophore , biomolecule , quenching (fluorescence) , chemistry , quantum yield , ferric , biophysics , nanotechnology , combinatorial chemistry , photochemistry , materials science , biochemistry , inorganic chemistry , biology , nitrogen fixation , nitrogen , organic chemistry , physics , nitrogenase , quantum mechanics , gene
Siderophores are bio‐organic ligands secreted by microbes to chelate and assimilate iron to meet their metabolic requirements. Siderophores and their analogs have tremendous therapeutic and analytical potential including the use as Fe (III) biosensors; however, only few practical applications have been realized. The aim of this study was the optical and biophysical characterization of the siderophore azotobactin (Az) secreted by the nitrogen‐fixing bacteria Azotobacter vinelandii. The peptide exhibited fluorescence in the visible range. Quantum yield and lifetime in excited state were measured to ascertain the sensitivity of the molecule as a fluorescent marker in biochemical assays. Its high affinity toward iron in the ferric state was demonstrated through fluorescence emission quenching studies. The accuracy of azotobactin as biosensing tool was determined by analyzing the levels of iron in biological fluids, particularly in human serum. Furthermore, it was demonstrated that it can be encapsulated in sol–gel matrices without significant loss of its fluorescence signal, thus enabling it suitable for adaptation to optical biosensor for Fe (III).