Preparation and characterization of ethylenediamine and cysteamine plasma polymerized films on piezoelectric quartz crystal surfaces for a biosensor

• Published in: Thin solid films 2008-01, Vol.516 (6), p.1249-1255
• Main Authors: Mutlu, Selma, Çökeliler, Dilek, Shard, Alex, Goktas, Hilal, Ozansoy, Berna, Mutlu, Mehmet
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cysteamine; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electric discharges; Electron beam; Exact sciences and technology; General equipment and techniques; Glow discharge; Glow; corona; Histamine; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma polymerized films; Quartz crystal; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Vitaceae
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2007.06.074

This paper describes a method for the modification of quartz crystal surfaces to be used as a transducer in biosensors that allow recognition and quantification of certain biomolecules (antibodies, enzymes, proteins, etc). Quartz crystal sensors were modified by a plasma based electron beam generator in order to detect the level of the toxin histamine within biological liquids (blood, serum) and food (wine, cheese, fish etc.). Cysteamine and ethylenediamine were used as precursors in the plasma. After each modification step, the layers on the quartz crystal were characterized by frequency measurements. Modified surfaces were also characterized by contact angle, X-ray photoelectron spectroscopy and atomic force microscopy to determine the physical and chemical characteristics of the surfaces after each modification. Finally, the performance of the sensors were tested by the response to histamine via frequency shifts. The frequency shifts of the sensors prepared by plasma polymerization of ethylenediamine and cysteamine were approximately 3230 Hz and 5630 Hz, respectively, whereas the frequency change of the unmodified crystal surface was around 575 Hz.