Immbolization of uricase enzyme in Langmuir and Langmuir-Blodgett films of fatty acids: Possible use as a uric acid sensor

• Published in: Journal of colloid and interface science 2012-05, Vol.373 (1), p.69-74
• Main Authors: Zanon, Nathaly C.M., Oliveira, Osvaldo N., Caseli, Luciano
• Format: Article
• Language: English
• Subjects: Adsorption; Air–water interface; Biocatalysis; biosensors; blood; Catalysis; Catalytic activity; Chemistry; Exact sciences and technology; General and physical chemistry; humans; Immobilization; Langmuir blodgett films; Membranes, Artificial; stearic acid; Stearic Acids - chemistry; Surface physical chemistry; Surface Properties; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Urate Oxidase - chemistry; Urate Oxidase - metabolism; uric acid; Uric Acid - analysis; Uric Acid - metabolism; Uricase
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2011.07.095

Several architectures of uricase-fatty acid ultrathin films were prepared and the enzyme activity investigated. [Display omitted] ► Uricase and fatty acids formed hybrid Langmuir monolayers. ► Films were transferred to solid supports as LB films in several architectures. ► Enzyme activity on uric acid was measured. ► One single enzyme–lipid layer transferred resulted in the best sensor. Preserving the enzyme structure in solid films is key for producing various bioelectronic devices, including biosensors, which has normally been performed with nanostructured films that allow for control of molecular architectures. In this paper, we investigate the adsorption of uricase onto Langmuir monolayers of stearic acid (SA), and their transfer to solid supports as Langmuir–Blodgett (LB) films. Structuring of the enzyme in β-sheets was preserved in the form of 1-layer LB film, which was corroborated with a higher catalytic activity than for other uricase-containing LB film architectures where the β-sheets structuring was not preserved. The optimized architecture was also used to detect uric acid within a range covering typical concentrations in the human blood. The approach presented here not only allows for an optimized catalytic activity toward uric acid but also permits one to explain why some film architectures exhibit a superior performance.