Application of Paper-Supported Printed Gold Electrodes for Impedimetric Immunosensor Development
In this article, we report on the formation and mode-of-operation of an affinity biosensor, where alternate layers of biotin/streptavidin/biotinylated-CRP-antigen/anti-CRPantibody are grown on printed gold electrodes on disposable paper-substrates. We have successfully demonstrated and detected the formation of consecutive layers of supra-molecular protein assembly using an electrical (impedimetric) technique. The formation process is also supplemented and verified using conventional surface plasmon resonance (SPR) measurements and surface sensitive characterization techniques, such as X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The article provides a possible biosensor development scheme, where—(1) fabrication of paper substrate (2) synthesis of gold nanoparticle inks (3) inkjet printing of gold electrodes on paper (4) formation of the biorecognition layers on the gold electrodes and (5) electrical (impedimetric) analysis of growth—all are coupled together to form a test-structure fora recyclable and inexpensive point-of-care diagnostic platform.
1 – Center of Excellence for Functional Materials and Laboratory of Physical Chemistry,Department of Natural Sciences, Åbo Akademi University, Turku, Finland
2 – Center of Excellence for Functional Materials and Physics, Department of Natural Sciences,Åbo Akademi University, Turku,
3 – Division of Biopharmaceutics and Pharmacokinetics, Faculty of Pharmacy, University of Helsinki,Helsinki, Finland
4 – Laboratory of Biophysics, Institute of Biomedicine and Medicity Research Laboratories,University of Turku, Turku, Finland
† – Current address: VTT Technical Research Center of Finland, Tietotie 3, Espoo 02150, Finland.