Characterisation of the topography and surface potential of electrodeposited conducting polymer films using atomic force and electric force microscopies

Barisci, Joseph N.; Stella, Rita; Spinks, Geoffrey M.; Wallace, Gordon G.

doi:10.1016/s0013-4686(00)00627-7

Cited by 68 publications

(48 citation statements)

References 25 publications

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“…Similarly, conductive AFM imaging of polybithiophene films has revealed higher conductivity in the nodules compared to the nodular periphery 29 . These observations are further supported by Kelvin Probe Force Microscopy (KPFM) of PPy/pTS films showing a more negative potential at the nodules and explained by these regions as having a higher work function, or increased doping, than their peripheries 27 . This characteristic phase separation in surface properties (e.g.…”

Section: Resultsmentioning

confidence: 57%

“…Single molecule studies take into account the multiplicity of protein interactions, especially in the case of large, modular FN protein that can exist in compact, semi-compact and extended conformations 25 , as well as having polyampholyte characteristics that makes it easily deformable on high charge density surfaces 26 . Furthermore, the complex surface properties of conducting polymers, due to different oxidation states 27 , inhomogenous 44 doping 28 and phase separation of properties (e.g. surface potential and conductivity) 29,30 , that have been shown to display nanoscale lateral variation are expected to amplify variations in the conformation and adhesion of individual proteins across the polymer surface.…”

Section: Introductionmentioning

confidence: 99%

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Quantifying fibronectin adhesion with nanoscale spatial resolution on glycosaminoglycan doped polypyrrole using Atomic Force Microscopy

Gelmi

Higgins

Wallace

2013

Biochimica et Biophysica Acta (BBA) - General Subjects

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The interaction of ECM proteins is critical in determining the performance of materials used in biomedical applications such as tissue regeneration, implantable bionics and biosensing. Methods: To improve our understanding of ECM protein-conducting polymer interactions, we have used Atomic Force Microscopy (AFM) to elucidate the interactions of fibronectin (FN) on polypyrrole (PPy) doped with different glycosaminoglycans. Results: We were able to classify four main types of FN interactions, including those related to 1) non-specific adhesion, 2) protein unfolding and subsequent unbinding from the surface, 3) desorption and 4) interactions with no adhesion. FN adhesion on PPy/hyaluronic acid showed a significantly lower density of surface adhesion with the adhesion restricted to nodule structures, as opposed to their peripheries, of the polymer morphology. In contrast, PPy/chondroitin sulfate showed a significantly higher density of surface adhesion to the point where the distribution of adhesion effectively masked the topography. Through conductive AFM imaging, we found that the conductive regions correlated with regions of FN adhesion. Conclusions: Given that the conductivity requires doping of the polymer, these findings suggest that FN adhesion is mediated by interactions with chondroitin sulfate and hyaluronic acid at the polymer surface and may be indicative of specific interactions due to contributions from electrostatic attraction between the FN and sulfate/anionic groups of the dopants. General significance: This study demonstrates the ability of AFM to resolve the protein-conducting polymer interactions at the molecular and nanoscale level, which will be important for interfacing these polymer materials with biological systems. This article is part of a Special Issue entitled Organic Bioelectronics -Novel Applications in Biomedicine.

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Section: Resultsmentioning

confidence: 57%

Section: Introductionmentioning

confidence: 99%

Quantifying fibronectin adhesion with nanoscale spatial resolution on glycosaminoglycan doped polypyrrole using Atomic Force Microscopy

Gelmi

Higgins

Wallace

2013

Biochimica et Biophysica Acta (BBA) - General Subjects

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“…para-toluene sulfonate (pTs) dopant was also tested, as previous neural recording data has shown it to have a high charge density and good acute recording performance 20 . Dodecylbenzenesulfonate (DBSA) dopant was also used, as it has a similar structure to pTs and had good cultured cell viability when used to dope polypyrrole [21][22][23] . PEDOT-PSS and PEDOT-DBSA were deposited for 4 different times (15,30,45 or 60 s), PEDOTpTs was deposited for 45s as recommended in our previous article 20 .…”

Section: Page 6 Of 24mentioning

confidence: 99%

Optical and Electrochemical Methods for Determining the Effective Area and Charge Density of Conducting Polymer Modified Electrodes for Neural Stimulation

et al. 2014

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Neural stimulation is used in the cochlear implant, bionic eye, and deep brain stimulation, which involves implantation of an array of electrodes into a patient's brain. The current passed through the electrodes is used to provide sensory queues or reduce symptoms associated with movement disorders and increasingly for psychological and pain therapies. Poor control of electrode properties can lead to suboptimal performance; however, there are currently no standard methods to assess them, including the electrode area and charge density. Here we demonstrate optical and electrochemical methods for measuring these electrode properties and show the charge density is dependent on electrode geometry. This technique highlights that materials can have widely different charge densities but also large variation in performance. Measurement of charge density from an electroactive area may result in new materials and electrode geometries that improve patient outcomes and reduce side effects. AbstractNeural stimulation is used in the cochlear implant, bionic eye and deep brain stimulation which involves implantation of an array of electrodes into a patient's brain. The current passed through the electrodes is used to provide sensory queues or reduce symptoms associated with movement disorders and increasingly for psychological and pain therapies. Poor control of electrode properties can lead to sub-optimal performance; however there are currently no standard methods to assess them, including the electrode area and charge density. Here we demonstrate optical and electrochemical methods for measuring these electrode properties and show the charge density is dependent on electrode geometry. This technique highlights that materials can have widely different charge densities, but also large variation in performance. Measurement of charge density from an electroactive area may result in new materials and electrode geometries that improve patient outcomes and reduce side-effects.

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“…Fig. 3a shows poly(1,3-DAB) film synthesized directly on a platinum foil having a thickness of 0.025 mm and it reveals the presence of the typical globular structure of the electrosynthesized polymers [21]. In any case this nodular arrangement produces a dense and overlapped polymeric film (Fig.…”

Section: Morphological Characterizationmentioning

confidence: 95%

Synthesis and characterization of polymeric films and nanotubule nets used to assemble selective sensors for nitrite detection in drinking water

Biagiotti

Valentini

Tamburri

et al. 2007

Sensors and Actuators B: Chemical

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Platinum electrodes were modified by electropolymerized films and polymer nanotubule nets and were applied to nitrite detection in drinking water. Several analytical parameters were investigated such as: different monomers (1,2-, 1,3-, 1,4-DAB, pyrrole, o-anisidine, 1,8-DAN), permeability toward nitrites and other interferences, permselectivty toward nitrites, operational and long-term stability. The best performances were obtained with a poly(1,3-DAB) film and the assembled sensor was characterized morphologically by scanning electron microscope and electrochemically by cyclic voltammetry and amperometry coupled to flow injection analysis (FIA), in terms of linear range of concentration (10-1000 M), limit of detection (2 M), reproducibility (R.S.D.%: 0.4) and linear regression (y ( A) = 1.14x ( M) + 2.6). Finally real samples (tap and mineral drinking water) were analyzed by adding standard nitrite solutions and the recovery was evaluated showing no matrix effect on sensor performances.

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Characterisation of the topography and surface potential of electrodeposited conducting polymer films using atomic force and electric force microscopies

Cited by 68 publications

References 25 publications

Quantifying fibronectin adhesion with nanoscale spatial resolution on glycosaminoglycan doped polypyrrole using Atomic Force Microscopy

Quantifying fibronectin adhesion with nanoscale spatial resolution on glycosaminoglycan doped polypyrrole using Atomic Force Microscopy

Optical and Electrochemical Methods for Determining the Effective Area and Charge Density of Conducting Polymer Modified Electrodes for Neural Stimulation

Synthesis and characterization of polymeric films and nanotubule nets used to assemble selective sensors for nitrite detection in drinking water

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