Switchable bioelectronics

Abstract

We review the rapidly emerging field of switchable interfaces and its implications for bioelectronics. We seek to piece together early breakthroughs and key developments, and highlight and discuss the future of switchable bioelectronics by focusing on bio-electrochemical processes based on mimicking and controlling biological environments with external stimuli. All these studies strive to answer a fundamental question: "how do living systems probe and respond to their surroundings? And, following on from that: "how one can transform these concepts to serve the practical world of bioelectronics?" The central obstacle to this vision is the absence of versatile interfaces that are able to control and regulate the means of communication between biological and electronic systems. Here, we review the overall progress made to date in building such interfaces at the level of individual biomolecules and focus on the latest efforts to generate device platforms that integrate bio-interfaces with electronics.

Interfacing nanomaterials for bioelectronic applications

“…1,2 In parallel with technological achievement in the area of electronics, the area offers significant biochemical and biotechnological progress in the design of novel biomaterials by providing unique ways to synthesise and/or engineer new biomolecules. These novel materials provide wide range of possibilities for their integration with electronic el ements.…”

“…1 The ability to control and modulate interfacial chemical and physical properties is crucial in most of these areas. Various materials have been used to create such interfaces and different characterisation methods have been deve loped to understand the interfacial properties of switchable interfaces.…”

“…1,7 The interface should be first a "good host" for the biomolecules. For example, if the biomolecule is a protein, the activity should remain as close to the native activity as possible, or if the biomolecule is DNA, the structure and composition should remain more or less same after each interaction.…”

“…Magnetic nanoparticles with different size, shape and surface functionalisation have been used in the area of magnetic resonance imagining (MRI), drug delivery, nano carriers and for separation of biomolecules. 1 The most common way to use magnetic nanoparticles in the area of bioelectronics is to modify their surface with different redox-active molecules such as ferrocyanide or some ferrocene derivatives, to make use of their electrochemical mediating properties and control biomolecular interaction at the inte rface. 113 Following this approach, researchers have recently developed various power-on-demand biofuel cells and biosensor devices.…”

“…The morphology and wettability changes of the structure on the surface, whether SAM or polymeric film, are mostly responsible for the behaviour of switchable interfaces, which allow control of the diffusibility of ions, analytes or redox species at the surface. 1,110 Temperature switchable bio-interfaces are usually established to reversibly control molecular recognition events, cell attachment to solid surfaces or e nzyme-based biocatalysis. The most commonly used polymer in these systems is poly(N-isopropylacrylamide-PNIPAAM).…”