The biosensor responses to the same concentration of urea for different types of immobilization. Typical responses to 0.5 mM urea obtained with biosensors created by urease immobilization in GA vapour (A), adsorption on the surface of transducer covered with: monolayer of silicalite (B), monolayer of nano beta zeolite (C), monolayer of zeolite L (D), monolayer of calcinated nano beta zeolite (E). The measurements were carried out in 5 mM phosphate buffer solution (pH 7.4).
Shelyakina et al. Nanoscale Research Letters 2014 9:124 doi:10.1186/1556-276X-9-124