COMPETITIVE AMPEROMETRIC MORPHINE SENSOR-BASED ON AN AGAROSE IMMOBILIZED MOLECULARLY IMPRINTED POLYMER

A morphine-sensitive device was constructed based on a molecularly imp rinted polymer. The imprinted polymer exhibited recognition properties previously. A method of detection based on competitive binding was us ed to measure morphine in the concentration range 0.1-10 mu g/ml. A mo rphine concentration of 0.5 mu g/ml gave a peak current (by oxidation) of 4 nA. The method of morphine detection involves two steps. In the first step, morphine binds selectively to the molecularly imprinted po lymer in the sensor. In the second step, an electroinactive competitor (codeine) is added in excess, whence some of the bound morphine is re leased. The released morphine is detected by an amperometric method. T he advantages of this type of sensor compared to biosensors based on a ntibodies, enzymes or cells are discussed. This sensor, based on an ar tificial recognition system, demonstrates autoclave compatibility, lon g-time stability and resistance to harsh chemical environments.