No abstract

The electrochemical behavior of the 2,2‘-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), a reversible redox probe, has been examined after it has been intercalated into the interlayer spacing of anionic clays (also called layered double hydroxides, LDH). The cyclic voltammetry response of [Zn-Cr-ABTS] and [Zn-Al-ABTS] LDHs modified electrodes was compared to that obtained with ABTS adsorbed species on [Zn-Cr-TA] and [Zn-Al-TA] LDHs where TA = terephthalate anion. The stable radical ABTS•+ intercalated in the LDHs structure was studied by UV−visible spectroelectrochemistry.

This review highlights the current research on the interactions between biological cells and Layered Double Hydroxides (LDH). The as-prepared biohybrid materials appear extremely attractive in diverse fields of application relating to health care, environment and energy production. We describe how thanks to the main features of biological cells and LDH layers, various strategies of assemblies can be carried out for constructing smart biofunctional materials. The interactions between the two components are described with a peculiar attention to the adsorption, biocompatibilization, LDH layer internalization, antifouling and antimicrobial properties. The most significant achievements including authors' results, involving biological cells and LDH assemblies in waste water treatment, bioremediation and bioenergy generation are specifically addressed.

Amperometric biosensor based on the entrapment of polyphenol oxidase within a laponite clay coating and crosslinked by glutaraldehyde is described for catechol detection. Laponite provides a hydrophilic enzyme surrounding increasing the long term stability of the biosensor compared to the corresponding biosensors obtained by chemical cross-linking of PPO with glutaraldehyde. Azure B, a cationic dye exchanged within the clay matrix, is used as an electron shuttle allowing the mediated detection of phenol derivatives at À 0.05 V. The detection limits obtained with the optimized biosensor configuration for catechol, p-cresol and phenol are 1, 1 and 17 nM, respectively.