Thin bacteria/Layered Double Hydroxide films using a layer-by-layer approach

[Display omitted] •Preparation of {bacteria/LDH}n thin films on ITO electrode by a layer-by-layer deposition method.•Thin films are formed by electrostatic interactions between Pseudomonas ADP and LDH nanosheets.•UV–Vis spectroscopy shows a progressive assembly process.•The metabolic activity of immobilized ADP is determined by chronoamperometry using Fe(CN)63−. This paper reports the design of thin bacteria/Layered Double Hydroxides (LDH) films in which bacterial cells of Pseudomonas sp. strain ADP were assembled alternatively with Mg2Al-NO3 LDH nanosheets by a layer-by-layer deposition method. The UV–Vis spectroscopy was used to monitor the assembly process, showing a progressive increase in immobilized bacteria amount upon deposited cycles. The {ADP/LDH}n film was characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy and atomic force microscopy. The metabolic activity of immobilized bacteria was determined using chronoamperometry by measuring the biochemical oxygen demand in presence of glucose using an artificial electron acceptor (Fe(CN)63−) at 0.5V/Ag-AgCl. A steady current of 0.250μAcm−2 was reached in about 30s after the addition of 5mM glucose.