No abstract

We demonstrate a simple route to versatile electrically addressable conductive polymer graft copolymer systems. The monomer of poly(3,4-ethylenedioxythiophene), one of the commercially most important conductive polymers, was modified by the addition of an ATRP-initiating site to grow brushes from. The modified monomer is easily accessible by a one-step synthesis from the commercially available 2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methanol. The modified monomer is subsequently electropolymerized onto large area gold-coated electrodes and utilized as a backbone for grafting pH-responsive poly(acrylic acid) brushes from.

This work demonstrates polymer brushes grafted from conductive polymer films which display dynamic surface switching dependent on salt, temperature and electrode potential. The electroactivity presented by the conductive polymer and the responsiveness of the grafted brushes leads to an interface with multiple control parameters. Here, we demonstrate this concept by grafting of uncharged brushes of poly(ethylene glycol)methyl ether methacrylates from conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT), and observe a temperature-and salt-induced switch of brush conformation, and their effect on the electrochemistry of the material. The switching conditions can be tailored by copolymerizing monomers with different numbers of ethylene glycol units. In addition, these surfaces exhibit antifouling properties, leading to potential applications such as electrically-addressable biointerfaces. Conductive surfaces with dynamic switching in response to temperature and salt † This work demonstrates polymer brushes grafted from conductive polymer films which display dynamic surface switching dependent on salt, temperature and electrode potential. The electroactivity presented by the conductive polymer and the responsiveness of the grafted brushes leads to an interface with multiple control parameters. Here, we demonstrate this concept by grafting of uncharged brushes of poly(ethylene glycol)methyl ether methacrylates from conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT), and observe a temperature-and salt-induced switch of brush conformation, and their effect on the electrochemistry of the material. The switching conditions can be tailored by copolymerizing monomers with different numbers of ethylene glycol units. In addition, these surfaces exhibit antifouling properties, leading to potential applications such as electrically-addressable biointerfaces.

Conducting polymers (CPs) are materials with unique optoelectronic properties that are employed in both chemical sensing and biosensing. A variety of electrochemical and optical biosensor designs have been developed based on CPs, due to their simple fabrication and direct readout methodologies. Efforts have been directed toward achieving high sensitivity, low detection limits, and superior selectivity for target molecules, which are the main considerations when evaluating a biosensor. As the capabilities of nanofabrication expand, nanoscale CP materials, such as nanowires and nanotubes, have been utilized to improve the performance of CP‐based biosensors. Simultaneously, multiple target detection through biosensor arrays has sped up developments in the field. This article gives an overview of recent designs in electrochemical biosensors utilizing CPs as active sensing elements in different formats, including array sensors. We discuss aspects of CP‐based biosensing where further research is needed to advance their performance, including sensitivity, selectivity, stability, and pretreatment of analyst.

Electrochemical water splitting is a sustainable, environmentally friendly method of hydrogen generation for green energy. However, the ideal electrocatalyst, platinum, is limited by cost and scarcity. Thus, new approaches are needed to minimize the amount of platinum required for efficient hydrogen production, while its electrocatalytic activity is retained. In this work, we report the development of a novel electrocatalyst based on platinum nanoparticles (PtNPs) deposited on conducting poly(3,4-ethylenedioxythiophene) (PEDOT), grafted with poly(acrylic acid) (PAA) chains. The presence of PAA controls the PtNP size and prevents aggregation during electrodeposition. The composite materials demonstrated enhanced electrocatalytic activity for the hydrogen evolution reaction (HER) in acid, with onset potentials as low as −84 mV vs RHE and exchange current densities up to 161 μA cm −2 . Thus, these composite electrodes show promise as a straightforward, cost-effective alternative to conventional platinum HER catalysts. Furthermore, this novel fabrication approach shows great potential for the development of future electrocatalysts, providing an infinitely tailorable substrate for nanoparticle deposition thanks to the versatility of grafted conducting polymer films.

No abstract

Our work on conductive polymer (CP) systems grafted with stimuli-responsive polymer brushes is motivated by the prospect of precisely controlling cellular behaviour by tailored smart interfaces. Here, the effects on cell adhesion by applying a potential to poly(3,4-ethylenedioxythiophene) (PEDOT) during both protein coating and cell culture is investigated. The results highlight the importance of pre-adsorbing fibronectin in this case, especially for the reduced polymer which binds protein strongly. The effects of changing the surface chemistry of the PEDOT electrode by grafting of brushes by atom transfer radical polymerisation (ATRP) is also investigated. Specifically, the composition of the salt-sensitive poly(oligo(ethylene glycol methyl ether methacrylate))-based brushes was tailored to control the level of cell adhesion to the interface. The composition, and also the length of the grafted brushes was seen to be important to the cell adhesion. It is also demonstrated how PEDOT films grafted with a protein and cell rejecting brush can be converted to a cell adhesive state by attaching an integrin ligand to the brush to mediate cell adhesion.

Grafting of polymer brushes from conducting polymer (CP) thin films by controlled radical polymerisation provides a versatile route for the synthesis of functional, electroactive surfaces, with applications in diverse fields. However, one of the drawbacks of this approach is the difficulty of upscaling the synthesis due to the need for specialised CP precursor monomers functionalised with initiation sites. We herein describe an alternative approach to the synthesis of CP-based polymer brushes whereby atom transfer radical polymerisation initiation sites are attached to a macrodopant incorporated into CP films during electropolymerisation. The facile electropolymerisation of commonly studied CPs with an initiator-functionalised macrodopant -poly[(styrene sulfonate)-co-(2-bromopropionyloxyethyl methacrylate)] -is demonstrated. The composite polymer films thus synthesised were used as substrates for grafting of hydrophilic polymer brushes. Although poly(styrene sulfonate) is commonly used as a macrodopant in CP films, its initiator-functionalised derivatives have not previously been utilised in this manner. Despite the elegance of this approach, to the authors' knowledge, there have been no previous examples reported of utilising macromolecular dopants as initiators for subsequent grafting of polymer brushes.