This work presents new amperometric bienzymatic bioelectrodes for the determination of organophosphorus and carbamic acid type pesticides. Two different kinds of bienzymatic bioelectrodes are presented: a classical bienzymatic electrode, obtained by physicochemical immobilization of purified acid phosphatase (AP) and glucose oxidase (GOD) on the tip of an amperometric H2O2 electrode; and a hybrid biosensor, in which AP has been employed in the form of a thin layer of potato (Solanum tuberosum) tissue, endowed with a high content of enzyme activity. Both the biosensors can selectively detect glucose-6-phosphate (G6P), in the 5.0 × 10−5 −1.2 × 10−3M concentration range. Pesticides are detected, thanks to their high inhibition power towards AP, evaluated by adding the sample stepwise to a buffered solution of G6P, and recording the corresponding current change. The detection limit is therefore a function of the type of pesticide, but it can be as low as 1 μg 1−1 in the case of organophosphorus compounds. The detection limit is generally higher for carbamates, as a consequence of their weaker inhibition power towards acid phosphatase. Both bioelectrodes presented comparable values of the main physicochemical and analytical parameters evaluated for assessing their overall performance; nonetheless the plant tissue based bioelectrode exhibited a longer shelf life and a better reliability of the amperometric results.
Acid Phophatase/Glucose Oxidase Based Biosensors for the Determination of Pesticides / Mazzei, Franco; Botre', Francesco; Botre', Claudio. - In: ANALYTICA CHIMICA ACTA. - ISSN 0003-2670. - STAMPA. - 336:1/3(1996), pp. 67-71. [10.1016/S0003-2670(96)00378-9]
Acid Phophatase/Glucose Oxidase Based Biosensors for the Determination of Pesticides.
MAZZEI, Franco;BOTRE', Francesco;BOTRE', Claudio
1996
Abstract
This work presents new amperometric bienzymatic bioelectrodes for the determination of organophosphorus and carbamic acid type pesticides. Two different kinds of bienzymatic bioelectrodes are presented: a classical bienzymatic electrode, obtained by physicochemical immobilization of purified acid phosphatase (AP) and glucose oxidase (GOD) on the tip of an amperometric H2O2 electrode; and a hybrid biosensor, in which AP has been employed in the form of a thin layer of potato (Solanum tuberosum) tissue, endowed with a high content of enzyme activity. Both the biosensors can selectively detect glucose-6-phosphate (G6P), in the 5.0 × 10−5 −1.2 × 10−3M concentration range. Pesticides are detected, thanks to their high inhibition power towards AP, evaluated by adding the sample stepwise to a buffered solution of G6P, and recording the corresponding current change. The detection limit is therefore a function of the type of pesticide, but it can be as low as 1 μg 1−1 in the case of organophosphorus compounds. The detection limit is generally higher for carbamates, as a consequence of their weaker inhibition power towards acid phosphatase. Both bioelectrodes presented comparable values of the main physicochemical and analytical parameters evaluated for assessing their overall performance; nonetheless the plant tissue based bioelectrode exhibited a longer shelf life and a better reliability of the amperometric results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.