Stimuli-enabled zipper-like graphene interface for auto-switchable bioelectronics

- Stimuli-encoded zipper-like graphene oxide (GrO)/polymer interface was fabricated.
- The smart bioelectrodes switch upon triggering.
- A reversible on/off-switching of bio-electrocatalysis was observed on changing the pH.
- The zipper-like interfacial bioelectrochemical properties were also tuned over a modest change in temperature.

Graphene interfaces with multi-stimuli responsiveness are of particular interest due to their diverse super-thin interfacial behaviour, which could be well suited to operating complex physiological systems in a single miniaturised domain. In general, smart graphene interfaces switch bioelectrodes from the hydrophobic to hydrophilic state, or vice versa, upon triggering. In the present work, a stimuli encoded zipper-like graphene oxide (GrO)/polymer interface was fabricated with in situ poly(N-isopropylacrylamide-co-diethylaminoethylmethylacrylate), i.e., poly(NIPAAm-co-DEAEMA) directed hierarchical self-assembly of GrO and glucose oxidase (GOx). The designed interface exhibited reversible on/off-switching of bio-electrocatalysis on changing the pH between 5 and 8, via phase transition from super hydrophilic to hydrophobic. The study further indicated that the zipper-like interfacial bioelectrochemical properties could be tuned over a modest change of temperature (i.e., 20-40 °C). The resulting auto-switchable interface has implications for the design of novel on/off-switchable biodevices with 'in-built' self-control.