BIOSENSORS WITH IMMOBILIZED PENICILLIN AMIDOHYDROLASE AND PENICILLINASE FOR DETERMINATION OF BETA-LACTAM ANTIBIOTICS

pH-membrane electrodes with tridodecylamine as a hydrogen-ionophore we re used for the construction of beta-lactam antibiotics biosensors. Th e electrodes were enzymaticaly sensitized using penicillin amidohydrol ase and penicillinase. Carboxylated poly(vinyl chloride) matrix of pH membranes allowed direct covalent binding of the enzyme. beta-lactam a ntibiotics biosensors with extended life-time (over two months) were o btained. Both types of biosensors allow determination of beta-lactam a ntibiotics within the concentration range from 0.1 to 30 mmol l(-1). T he steady-state response times were 2.5 min and 1.5 min for the biosen sors with immobilized penicillin amidohydrolase and penicillinase, res pectively. The selectivity of both types of biosensors with respect to various beta-lactam antibiotics is different.