An ionogel composite including copolymer nanowires for disposable electrochemiluminescent sensor configurations

Abstract

Aniline derivatives such as luminol and benzidines can be electropolymerized for the preparation of electrochemiluminescent sensors. However, the development of these sensors requires formulations to improve the chemical stability and photoemissive and electrochemical properties. The use of ionic liquids confined in gels (ionogels) can provide a material for electrochemiluminescent sensor preparation and more specifically by means of hybrid organic–inorganic composites which provide flexibility, thermal stability, and ionic transport. By using this configuration, we prepared nanowires of luminescent polymers by electropolymerization in the pores of a hydrophilic silica ionogel with chitosan, offering a biocomposite that can be prepared in disposable screen-printed gold electrodes. The properties of the prepared biocomposite have been characterized by emissive luminescence, cyclic voltammetry, electrochemical quartz crystal microbalance and scanning electron microscopy. The results show that the electrochemiluminescent copolymer grows efficiently as nanowires in the pores of the biocomposite, forming sensing films that produce an intense luminescent blank signal due to the influence of the ionic liquid. Hydrogen peroxide was used as an analyte; it acts as a scavenger, reducing the emissive signal and resulting in a novel electrochemiluminescence configuration for sensing. This configuration broadens the field of electrochemiluminescence sensors due to the biocompatibility of the developed ionogel membrane.