Fredrik Björefors

  • Citations Per Year
Learn More
BACKGROUND ECG (Electrocardiogram) measurements in home health care demands new sensor solutions. In this study, six different configurations of screen printed conductive ink electrodes have been evaluated with respect to electrode potential variations and electrode impedance. METHODS The electrode surfaces consisted of a Ag/AgCl-based ink with a(More)
Reversible assembly of gold nanoparticles controlled by the homodimerization and folding of an immobilized de novo designed synthetic polypeptide is described. In solution at neutral pH, the polypeptide folds into a helix-loop-helix four-helix bundle in the presence of zinc ions. When immobilized on gold nanoparticles, the addition of zinc ions induces(More)
Electrochemical impedance spectroscopy has been used to evaluate the change in interfacial capacitance upon calcium and magnesium coordination to a phosphate-modified electrode. The phosphate electrode was prepared via immobilization of phosphorylated, thiol-containing, serine analogues onto gold. Upon subjection to calcium and magnesium, a substantial drop(More)
A series of alkylthiol compounds were synthesized to study the formation and structure of complex self-assembled monolayers (SAMs) consisting of interchanging structural modules stabilized by intermolecular hydrogen bonds. The chemical structure of the synthesized compounds, HS(CH(2))(15)CONH(CH(2)CH(2)O)(6)CH(2)CONH-X, where X refers to the extended chains(More)
This paper deals with the use of reaction gradients on bipolar electrodes for the patterning of electrode surfaces.More specifically, the potential and current density distributions in two setups containing bipolar electrodes were investigated to optimize and design specific gradient geometries. Comparisons with simulations based on simple conductivity(More)
Gold surfaces and structures modified with octanedithiol were reacted with dithiothreitol prior to immersion in buffered solutions of charge stabilized gold nanoparticles. The procedure gives a dithiol layer with adequate properties for a homogeneous octanedithiol monolayer and uniform and reproducible gold nanoparticle binding. The distance between the(More)
Mattias Samuelsson, Daniel Lundin, Kostas Sarakinos, Fredrik Bjorefors, Bengt Walivaara, Henrik Ljungcrantz and Ulf Helmersson, Influence of ionization degree on film properties when using high power impulse magnetron sputtering, 2012, Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, (30), 3, 031507.(More)
An electrolyte based on the new salt, lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide (LiTDI), is evaluated in combination with nano-Si composite electrodes for potential use in Li-ion batteries. The additives fluoroethylene carbonate (FEC) and vinylene carbonate (VC) are also added to the electrolyte to enable an efficient SEI formation. By employing(More)
The formation of highly ordered self-assembled monolayers (SAMs) on gold from an unusually long and linear compound HS(CH(2))(15)CONH(CH(2)CH(2)O)(6)CH(2)CONH(CH(2))(15)CH(3) is investigated by contact angle goniometry, ex situ null ellipsometry, cyclic voltammetry and infrared reflection-absorption spectroscopy. The molecules are found to assemble in an(More)