Liquid photopolimerized compositions as immobilization matrix for biosensors
|Nickolaj F. Starodub 1, Andrij V. Rebrijev|
1. Ukrainian National Academy of Sciences, A. V. Palladin Institute of Biochemistry, 9 Leontovicha, Kyiv 01030, Ukraine
Series of liquid photopolimerized compositions (LPhPC) based on oligouretanemetacrylate (OUM-1000T and OUM-2000T) and oligocarbonatemetacrylate (OCM-2), monomethacrylic ether of ethylen glycol and vinylpirrolidone (VP) were tested. It was shown that the optimal LPhPC contained VP (as basic hydrophylic matrix), OCM-2 (crosslinked agent) and OUM-2000T (crosslinked and increasing adsorption of polymer). The blend contained 3% of enzyme. ISFETs based biosensors for glucose or urea had following charachteristics: response was linear in the the concentration of 0,1-10 mM, 0,05-20 mM, slope angle of curve - 30 mV/pC, 38 mV/pC, and response time - 10-15, 5-10 min, correspondingly. Km for immobilised urease and β-glucose oxidase (GOD) achieved values of 0,85 and 3,1 mM, respectively. The residual activity of enzymes in LPhPC was studied. Under conditions of the immobilization at 20 ºC GOD residual activity is about 35 % from an initial level, horseredish peroxidase and urease - 42% and 20%, respectively. In case of GOD immobilization at -50ºC its residual activity reaches almost 50% from initial level. It was investigated the influence of different sources of UV-radiation and different substances (including specific and non-specific substrates) on stability of the enzymes in the LPhPC and in the prepared membrane at storage. Dynamic of changes of enzyme activity at the process of photoimmobilization was characterized, and also the requirements for providing of its maximal storage was selected. So, it was proposed the optimal conditions for preparation of LPhPC to meet biosensorics demands in respect of non-active for biological substances, permeability for analytes, defined hydrophobic-hydrophilic balance, sufficient level of adhesion to transducer surfaces, simplicity of immobilization process and homogeneity of formed membrane.The proposed LPhPC may be preliminary prepared since enzymes did not lost or lost a few bit their activity during 2 month and it may be used for combination of two processes: manufacturing transducers and simultaneous biological membrane preparation by traditional approach of modern electronics - photolithography.
Presentation: Keynote lecture at SMCBS'2005 Workshop, by Nickolaj F. Starodub
See On-line Journal of SMCBS'2005 Workshop
Submitted: 2005-07-29 15:55 Revised: 2009-06-07 00:44