Alkaline phosphatase biosensors based on layered double hydroxides matrices: Role of LDH composition

Alkaline phosphatase (AlP) biosensors were developed based on the immobilization of this enzyme by adsorption or coprecipitation methods in different layered double hydroxides (LDH) matrices: Zn2Al-Cl and Mg2Al-CO3. Several characteristics of the AlP/LDH membranes, such as the enzyme immobilizadon Procedure, permeability, buffering effect were investigated. It appeared that the basic nature of the MgAl-LDH nanomaterial improved the stability of the immobilized AIP regarding pH. The synergy between the LDH immobilization matrix and the use of hydroquinone diphosphate (HQDP) as substrate provided a very fast and stable response for the AlP/MgAl-LDH biosensors at O.4V. (C) 2008 Elsevier B.V. All rights reserved.