Biosensor to detect chromium in wastewater

Abstract

A urease based biosensor for the determination of chromium ions in wastewater using modified sol gel immobilization technique was developed. Crude urease from Dolichos uniflorus immobilized on non woven cellulose swab was used as the bio recognition element. The maximum velocity (Vm) decreased from 10.62 mM/min for the free urease to 3.28 × 10−3 mM/min for the immobilized urease, while the change in the saturation constant (Km) was from 20.044 mM to 22.049 mM. The performance of the sensor was evaluated and the factors affecting inhibition and immobilization of the enzyme were investigated. The sensor was operational when used for six times after which the operational stability reduced by 6%. The sensor could be stored for four days after which the storage stability decreased by 2%. The activity of the immobilized urease was restored up to 12% of its original activity after inhibition by chromium. The biosensor developed showed high reproducibility when tested with water samples. © 2007 Taylor and Francis Group, LLC.