Type 2 pyoverdine fromPseudomonas aeruginosastrain BUP2 asturn-offbiosensor for the rapid detection of iron and copper ions in contaminated water.
Employing fluorescent quenching mechanism, type 2 pyoverdine (PVD) purified fromPseudomonas aeruginosastrain BUP2 (new strain isolated from the rumen of Malabari goat) was used as a simple, convenient and inexpensive tool for the rapid detection of Fe and Cu ions in contaminated drinking water samples. The fluorescence emitted at λ460by PVD (in sterile water), mounted on a glass slide was efficiently quenched by the ions of heavy metals like Fe and Cu. The fluorescence quenching effect of PVD was monitored using UV trans-illuminator, and subsequently quantified and confirmed by spectrofluorimetry. Upon exposure for about 50 sec at 25 °C, this quenching efficiency could directly be assessed by naked eye with the aid of a UV trans-illuminator. The linear range of detection for Fe was 1 to 60 µM, while that of Cu was 1 to 20 µM. The limits of detection at µM concentration for Fe3+, Fe2+and Cu2+were 0.23, 0.24 and 0.38, respectively. The quenching of fluorescence was more pronounced in Fe-PVD system than Cu-PVD, and this observation was in corroboration with the Pearson acid base concept; being a hard acid, Fe3+effectively bound with the O-ligands and this ability was less in Cu2+, a border line acid. Briefly, this study proposed the use of type 2 PVD as aturn-offbiosensor for the rapid screening of heavy metals like Fe and Cu in drinking water, at ppm levels only with the aid of UV trans-illuminator at 25 °C in 50 sec.
Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, School of Biosciences, University of Calicut, Kerala -673635, India.
Kizhakkepowathial Nair
KN
Unni
Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, School of Biosciences, University of Calicut, Kerala -673635, India.
Prakasan
P
Priji
Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, School of Biosciences, University of Calicut, Kerala -673635, India.
Sreedharan
S
Sajith
Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, School of Biosciences, University of Calicut, Kerala -673635, India.
Panichikkal Abdul
PA
Faisal
Department of Chemistry, University of Calicut, Kerala -673635, India.
Karippayi Mattil
KM
Shainy
Department of Chemistry, University of Calicut, Kerala -673635, India.
Abraham
A
Joseph
Department of Statistics, Government Arts and Science College, Kozhikode, Kerala - 673018, India.
Moolath Girish
MG
Babu
Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, School of Biosciences, University of Calicut, Kerala -673635, India.
Sailas
S
Benjamin
Fe, Cu metal ions; Pseudomonas aeruginosa BUP2; fluorescence detection; turn-off biosensor; type 2 pyoverdine