HS-undecylcalixarenes as the receptors for detection of dopamine by quartz crystal microbalances
|Alexandra Poturnayová 1, Majka Šnejdárková 1, Tibor Hianik 2|
1. Institute of Animal Biochemistry and Genetics SASc, Moyzesova 61, Ivanka pri Dunaji 90028, Slovakia (Slovak Rep.)
Dopamin is neurotransmitter, which play significant role in the functioning of central nervous, renal and hormonal systems. Dopamine is also illegally used in the doping. Its concentration varied from 0,163 nM in the blood to 384-2360 nM in urine. The concentration of dopamine in the extracellular fluid of central nervous system is 0,01-1 µM. Development of sensitive method of detection dopamine is urgently needed for diagnosis and also in the purpose of anti-doping tests. Currently the detection of dopamine is based on electrochemical methods, HPLC, fluorimetry and capillary electroforesis.
Our approach is based on the detection of the dopamine by the quartz crystal microbalance (QCM) using thickness shear mode method (TSM). As a receptor we used 18.104.22.168-tetrakis(11-sulfanylundecyloxy) calixarene (calixarene) that has been chemisorbed on a gold surface of quartz crystal resonator. We studied the kinetics of the changes of the series resonant frequency, fs, and the motional resistance, Rm, of the quartz crystal transducer following addition of dopamine. We observed typically the decrease of fs and increase of Rm, following addition of dopamine. The increase of Rm suggests on increase of surface viscosity. The changes of both parameters started already at 53 pM of dopamine. The topography of the layers was investigated by atomic force microscopy in taping magnetic mode. The images of the calixarene layers in an air environment revealed smooth surface with irregular pinholes.ACKNOWLEDGMENTS This work was financially supported by Agency for Promotion Research and Development under the contract No. APVV-0362-07 and by Slovak Grant Agency (Projects No.VEGA 2/7134/27, VVCE-0064-07 M. Š. and No. 1/4016/07 to T.H. The Calixarenes was a gift from Prof. P. Lhoták from Institute of Chemical Technology, Department of Organic Chemistry, Prague, Czech Republic).
Presentation: Poster at SMCBS'2009 International Workshop, by Alexandra Poturnayová
See On-line Journal of SMCBS'2009 International Workshop
Submitted: 2009-08-21 09:44 Revised: 2009-08-21 09:55