| Autor: |
Cheng R; School Ophthalmology & Optometry, School of Biomedicine Engineering, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China., Colombo RNP; Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, Brazil., Zhang L; School of Chemistry, Australia Centre for NanoMedicine, ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of New South Wales, Sydney NSW2052, Australia., Nguyen DHT; School of Chemistry, Australia Centre for NanoMedicine, ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of New South Wales, Sydney NSW2052, Australia., Tilley R; School of Chemistry, Australia Centre for NanoMedicine, ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of New South Wales, Sydney NSW2052, Australia.; Electron Microscopy Unit, Mark Wainwright Analytical Centre, The University of New South Wales, Sydney NSW2052, Australia., Cordoba de Torresi SI; Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000 São Paulo, Brazil., Dai L; School of Chemistry Engineering, The University of New South Wales, Sydney NSW2052, Australia., Gooding JJ; School of Chemistry, Australia Centre for NanoMedicine, ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of New South Wales, Sydney NSW2052, Australia., Gonçales VR; School of Chemistry, Australia Centre for NanoMedicine, ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, The University of New South Wales, Sydney NSW2052, Australia. |
| Abstrakt: |
Porous materials can be modified with physical barriers to control the transport of ions and molecules through channels via an external stimulus. Such capability has brought attention toward drug delivery, separation methods, nanofluidics, and point-of-care devices. In this context, gated platforms on which access to an electrode surface of species in solution can be reversibly hindered/unhindered on demand are appearing as promising materials for sensing and microfluidic switches. The preparation of a reversible gated device usually requires mesoporous materials, nanopores, or molecularly imprinted polymers. Here, we show how the breath-figure method assembly of graphene oxide can be used as a simple strategy to produce gated electrochemical materials. This was achieved by forming an organized porous thin film of graphene oxide onto an ITO surface. Localized brushes of thermoresponsive poly( N -isopropylacrylamide) were then grown to specific sites of the porous film by in situ reversible addition-fragmentation chain-transfer polymerization. The gating mechanism relies on the polymeric chains to expand and contract depending on the thermal stimulus, thus modulating the accessibility of redox species inside the pores. The resulting platform was shown to reversibly hinder or facilitate the electron transfer of solution redox species by modulating temperature from the room value to 45 °C or vice versa. |
