Research Article
Neelam Verma, Sachin Kumar
Abstract
A novel absorption-transmission based, miniaturized fi ber optic biosensor has been developed for the detection of cadmium in milk. Biosensor constitutes Bacillus badius whole cells with phenol red as an indicator co-immobilized onto circular plastic discs with sol-gel approach and a fi ber optic transducer system. Inhibition of urease enzyme by cadmium ion has been used as bioassay principle in the study. The detection limit of 0.1 g/l has been achieved. Sample volume could be miniaturized to 10 l; miniaturization of sample volume to this level has never been cited in literature. Storage stability of biocomponent was found to be more than 90 days when stored at 4°C in 10% glycerol. Conclusively the study resulted in development of a quick, reliable, miniaturized biosensor with lower detection limit and longer storage stability.