This paper reviews recent developments in urea biosensors, as reported in the literature. The advantages and roles of various matrices, different strategies for biosensor construction, analytical performance and applications are discussed. The prospects of urea biosensors for medical applications are also discussed.
Detailed account of urea biosensors with interesting general observations on biosensor design. Urea is a good indicator of protein-feeding efficiency in cows, it plays a strategic role in the marine nitrogen cycle, and is widely used as a fertilizer. Risks: Excessive nitrogen fertilizer applications can lead to pest problems by increasing the birth rate of certain pests and can be responsible for reduction in soil pH. Detection: The analyte (urea) and enzyme (urease) result in a product (ammonium ion) that can be detected and quantified using a transducer. Various polymer matrices in urea biosensors described, including polyaniline (PANI): Fast and sensitive; provides easy modulation of various properties (e.g., film thickness, conductivity, functionalization, use of various supporting electrolytes and the ability of serving as an electrochemical transducer itself. Discussion of nanomaterials and several other carriers/matrices for urea biosensors. 154 references.
Gunjan Dhawan, Gajjala Sumana, B.D. Malhotra, “Recent developments in urea biosensors,” Biochemical Engineering Journal, Vol. 44, Iss. 1, 15 April 2009, p. 42-52