Different Methods of Acid Phosphatase Immobilization for Its Application in FIA Systems with Potentiometric Detection

Application of enzymatic catalysis in chemical analysis enables increase of selectivity, reduction of detection limits, lowering of analysis costs and duration. Enzymes in flow through analytical systems can be applied in two main configurations [1]. In the first of them, enzymes are immobilized on special carriers in flow-through reactor. The second possible configuration are biosensors (working as detectors), in which enzyme molecules are an integral part of sensor receptor layer. In both cases, enzyme immobilization is necessary to ensure multiple use of applied system.In presented work the possibility of application of novel fluoride selective electrodes, as detector in FIA systems utilizing enzymatic reactions in various configurations has been evaluated. Different methods of enzyme (Acid Phosphatase, EC 3.1.3.2) immobilization have been tested, including covalent bonding via -NH2 and -COOH groups (both on ion exchanger resin and sensor membrane) and cross linking with glutaraldehyde (CLEAs, cross linked enzyme aggregates).