In view of the extreme toxicity of uranium and consequent stringent limits fixed by WHO and various national governments, it is essential to monitor the uranium content in the environment which is at ultratrace levels. Conventional ionophore based ion selective electrodes, barring a few, have limitations in terms of sensitivity and selectivity for the above mentioned purpose. We now propose an ion imprinted polymer (biomimetic) based potentiometric sensor by dispersing the uranyl ion imprinted polymer particles in 2-nitrophenyloctyl ether (plasticizer), which is embedded in polyvinyl chloride matrix. The sensor responds to uranyl ion over a wide concentration range of 2.0 x 10(-8) to 1.0 x 10(-2) M. The limit of detection was 2.0 x 10(-8) M. It showed a good selectivity for uranyl ion over alkali, alkaline earth, transition and heavy metal cations. The sensor is successfully tested for the monitoring of toxic uranium in tap and sea water samples.