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A urea fiber optic biosensor based on absorption measurement

, : A urea fiber optic biosensor based on absorption measurement. Analytical Letters 23(12): 2143-2154

The newly developed urea fiber optic sensor is based on the determination of the enzymatically generated ammonia during the hydrolysis of urea by immobilized urease with the pH indicator, bromothymol blue, which strongly absorbs light at 620 nm when it is deprotonated. The sensor is reversible and responds linearly in the urea concentration range 0.25 mM to 8 mM with a correlation coefficient of 0.9940. The coefficient of variation of 10 duplicate measurements was 1.62% for a 6 mM urea solution. The proposed optrode can be used for about 100 assays with good reproducibiilty. The preparation is simple and its application in urea analysis is demonstrated. The total measurement time (5-16 minutes, depending on urea concentration) is about the same as that for a urea potentiometric biosensor.


DOI: 10.1080/00032719008052556

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