Author/Authors :
Reddy، Kalluru G. نويسنده Department of Chemistry, S.V.U. College of Sciences, Sri Venkateswara University,Tirupati-517502, Andhra Pradesh, India , , Madhavi، Gajulapalli نويسنده Department of Chemistry, S.V.U. College of Sciences, Sri Venkateswara University,Tirupati-517502, Andhra Pradesh, India , , Kumara Swamy، Bahaddurghatta E. نويسنده Department of P.G. Studies and Research in Industrial Chemistry, Kuvempu University, Jnana Sahyadri, Shankaraghatta, Shimoga, Karnataka 577451, India , , Jyothi، Patri J. نويسنده Department of Chemistry, S.V.U. College of Sciences, Sri Venkateswara University,Tirupati-517502, Andhra Pradesh, India , , Bhaskar Reddy، Ambavaram V. نويسنده Department of Chemistry, S.V.U. College of Sciences, Sri Venkateswara University,Tirupati-517502, Andhra Pradesh, India , , Reddy، Sathish نويسنده Department of P.G. Studies and Research in Industrial Chemistry, Kuvempu University, Jnana Sahyadri, Shankaraghatta, Shimoga, Karnataka 577451, India ,
Abstract :
Liquid state lipase enzyme sensor was used for the detection of Carbophenothion
and Dibrom organophosphorus pesticides and the electrochemical behavior of both the
pesticides was studied. The developed enzymatic method is based on in situ generation of
p-Nitrophenol by lipase enzymatic hydrolysis of p-Nitrophenyl Acetate substrate. The
electrochemically active p-Nitrophenol gives an anodic oxidation peak potential at 0.05 V vs.
SCE. Based on enzymatic inhibition property of Carbophenothion and Dibrom pesticides are
selected for study of lipase enzyme inhibition. The current response is based on the
production of p-Nitrophenol under the influence of enzyme concentration, substrate
concentration, pH and time variation effects were studied. A linear calibration for
Carbophenothion and Dibrom was obtained in the various concentration ranges of 10-100
ppb and 100-1000 ppb respectively with a correlation coefficient of 0.947 and 0.936 under
the optimized conditions by following the incubation time of 25 min. The electrochemical
experiments were performed in 0.1 M phosphate buffer solution (pH 7.0) at room
temperature. The limit of detection and limit of quantification values were found to be 37.40
ppb, 124.6 ppb and 371.7 ppb, 1239 ppb for Carbophenothion and Dibrom respectively under
optimized conditions. The pesticide carbophenothion is more toxic than the dibrom as
evidenced by the electrochemical studies. The developed liquid state lipase enzyme sensor
takes less time for the analysis and no preconcentration extraction was needed for the study.
