Peter Åsberg

Hydrogels of a conducting conjugated polymer as 3-D enzyme electrode.

We have utilized the highly conducting poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) aqueous dispersion (PEDOT/PSS) to build a conducting hydrogel matrix. Together with appropriate biomolecules this constitutes a hydrogel bio-electrode. The open hydrogel structure makes diffusion of analytes surrounding the cells into the matrix electrode easier. If enzymes are utilized, osmium is used as mediator between the prosthetic group of the enzyme and the conducting polymer matrix. Osmium also functions as a crosslink point to poly-4-vinylpyridine, which together with the magnesium crosslinked PEDOT/PSS gives a rigid hydrogel. The enzyme Horseradish peroxidase (HRP) was used as a model enzyme to evaluate the enzyme-enhanced electrode. We evaluated the electrode at pH 7, which is the pH choice for many biological systems. From cyclic voltammetry (CV) measurements we deduced that a very low reduction potential was needed to reduce the prosthetic group. Constant potential amperometry were performed to demonstrate the biosensor capabilities. A differential sensitivity of 0.13 A M(-1) cm(-2) through the 0-30 microM concentration range was achieved. Both the biostability and the influence on conductivity, important aspects when for example making nerve- or cell-electrodes, were investigated.

Bridging Dimensions in Organic Electronics : Assembly of Electroactive Polymer Nanodevices from Fluids

Processing and patterning of electroactive materials from solvents is a hallmark of flexible organic electronics, and commercial applications based on these properties are now emerging. Printing and ink-jetting are today preferred technologies for patterning, but these limit the formation of nanodevices, as they give structures way above the micrometer lateral dimension. There is therefore a great need for cheap, large area patterning of nanodevices and methods for top-down registration of these. Here we demonstrate large area patterning of connected micro/nanolines and nanotransistors from the conducting polymer PEDOT, assembled from fluids. We thereby simultaneously solve problems of large area nanopatterning, and nanoregistration.

Fluorescence quenching and excitation transfer between semiconducting and metallic organic layers

Here we present a simple approach to study the interaction of singlet excitons with polarons in conjugated polymers in organic electronic devices. Interlayer quenching constants KIL of 1.5 M−1 betw ...

Computer screen photo-assisted spectral fingerprinting of luminescent polythiophene pH reporter

The capability of the computer screen photo-assisted technique (CSPT) for the spectral fingerprinting of a photoactive polythiophene derivative (POWT), used as a pH reporter, is demonstrated. POWT is part of a family of industrial scalable materials, well established for organic electronics and biomedical applications, which is used here to demonstrate the capability of CSPT for tracing key spectral features. The ability of CSPT for substance classification, corroborated by principal component analysis (PCA), successfully compares to standard spectroscopy, especially considering the involved equipment: CSPT is only a computer set and a Web camera.