Porous Tin-Oxide-Coated Regenerated Cellulose as Disposable and Low-Cost Alternative Transducer for Urea Detection

This paper investigates the possibility of utilizing tin-oxide (SnO₂)-Coated regenerated cellulose as a disposable and low-cost alternative transducer for urea detection. A thin layer of SnO₂ is coated on regenerated cellulose films via liquid-phase deposition technique. Cellulose-SnO₂ hybrid nanocomposite urea biosensor is prepared by immobilizing urease on the SnO₂ layers by physical absorption method. The resulting biosensor shows a linear response up to 42 mM. Also it is found that the proposed sensor exhibits the same level of sensitivity for seven days; in other words, the sensitivity of the sensor did not degrade with time and remained same for 7 days. This urea sensor is inexpensive, flexible, and disposable.