PENICILLIN G AND OTHER -LACTAMIC ANTIBIOTICS DETEREMINATION USING A NEW IMMUNOSENSOR IN REAL SAMPLES

A number of analytical methods for penicillin control were developed in the last years, involving chromatographic techniques. Nevertheless the need for rapid and inexpensive tests has also encouraged the use of biosensor methods. In previous years, for instance, also the authors of the present communication developed some useful ISEs for analysing 0-lactamic antibiotics [1], although their selectivity was not particularly high. In more recent years therefore more specific enzymatic biosensors have been developed for the analysis of penicillin and other 0-lactamic antibiotics using penicillinase as enzyme and as transducer a sensor for pH measurement of different types: potentiometric (glass, metal-oxide, membrane electrodes, ISFET [2]), or fluorescence and absorbance optodes. The difficulty encountered in developing this type of enzymatic sensor is that found in all those biosensors in which a pH variation produced by an enzymatic reaction is to be measured even when having to operate practically in a pH buffered solution. Several kinds of immunosensors for clinical and