Polipirol-glikoz oksidaz biyosensörün hazırlanması ve deneysel parametrelerin optimizasyonu
Küçük Resim Yok
Tarih
1994
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
İnönü Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
in ÖZET Bu çalışmada, pirolün 0.8 V'luk bir potansiyel altında glikoz oksidaz içeren KC1 çözeltisi içerisindeki elektropolimerizasyonu (co-immobilization) ile amperometrik glikoz biyosensör hazırlanmış ye hazırlanan enzim elektrot, enzimatik reaksiyon sonucu oluşan hidrojen peroksiti yükseltgemek amacıyla 0.7 V potansiyelde tutularak glikoza karşı yanıt alınmıştır. Enzim elektrodun elektrokimyasal yanıtı üzerine değişik parametrelerin (film kalınlığı, monomer (pirol) derişimi, elektrolit derişimi, tampon derişimi, sıcaklık, pH, karıştırma hızı, v.s) etkisi sistematik olarak incelenerek bu parametrelere ait optimum değerler tesbit edilmiştir. Daha sonra, optimize edilmiş enzim elektrodun lineerliği, seçiciliği ve kararlılığı saptanarak, enzimatik reaksiyona ilişkin aktivasyon enerjisi hesaplanmıştır. Sonuç olarak, biyosensör yapımı için, 0.01 M KC1, 100U/ml GOD ve 0.25 M pirolün optimum şartlar olduğu ve optimal yanıtın, 0.777 um film kalınlığı, pH 7 ve 308 K'lik sıcaklıkta elde edildiği görülmüştür. Ayrıca amperometrik yanıtın sıcaklığa bağımlılığından enzimatik reaksiyona ilişkin aktivasyon enerjisinin 13 kj/mol olduğu bulunmuştur. Hazırlanan enzim elektrodun 2.5-15 mM glikoz derişimlerine lineer bir şekilde cevap verdiği ve sukroz, askorbik asit, süksinik asit, maleik asit gibi interferans etki yapan türlere karşı yanıt vermediği gözlenmiştir. Ayrıca, değişik bekletilme koşullan altında saklanan enzim elektrotların ömür ve işlemsel kararlılıkları peryodik olarak test edilmektedir.
IV ABSTRACT In this study, an amperometric glucose biosensor was prepared by the electropolymerization of pyrrole onto a platinium electrode in the presence of the enzyme glucose oxidase (GOD) in a KC1 solution at a potential of 0.8V vs. Ag/AgCl. The enzyme was incorporated into polypyrrole film during the electropolymerization process (Co-immobilization). Glucose response were measured by potentiostating the enzyme electrode at a potential of 0.7 V (vs. Ag/AgCl) in order to oxidize the hydrogen peroxide generated by the oxidation of glucose by the enzyme in the presence of oxygen. Effects of various parameters (film thickness, concentrations of monomer (pyrrole), electrolyte, enzyme and buffer, temperature, pH, stirring rate, e.g.) on the steady-state- electrochemical response of the prepared enzyme electrode were systematically investigated and the optimum values of these parameters were found. Then, linearity, selectivity and stability of optimized enzyme electrode were determined. Moreover, activation energy for enzymatic reaction was calculated. In conclusion, it was found that a concentration of 0.25 M pyrrole in the presence of 100U/ml of glucose oxidase in a 0.01 M KC1 solution, were the optimal parameters for the fabrication of the biosensor. The optimal response was obtained for film thickness of 0.777 jam at pH 7 and at a temperature of 308 K. The temperature dependence of the amperometric response indicated an activation energy of 13 kj/mole. The linearity of the enzyme electrode response ranged from 2.5 mM to 15 mM glucose. The specificity of the enzyme electrode was investigated for various substrates such as sucrose, ascorbic acid, succinic acid, maleic acid and no discrenible signal was detected above the background current. The shelf life and the operational stability of the enzyme electrodes under various storage conditions has been tested periodically.
IV ABSTRACT In this study, an amperometric glucose biosensor was prepared by the electropolymerization of pyrrole onto a platinium electrode in the presence of the enzyme glucose oxidase (GOD) in a KC1 solution at a potential of 0.8V vs. Ag/AgCl. The enzyme was incorporated into polypyrrole film during the electropolymerization process (Co-immobilization). Glucose response were measured by potentiostating the enzyme electrode at a potential of 0.7 V (vs. Ag/AgCl) in order to oxidize the hydrogen peroxide generated by the oxidation of glucose by the enzyme in the presence of oxygen. Effects of various parameters (film thickness, concentrations of monomer (pyrrole), electrolyte, enzyme and buffer, temperature, pH, stirring rate, e.g.) on the steady-state- electrochemical response of the prepared enzyme electrode were systematically investigated and the optimum values of these parameters were found. Then, linearity, selectivity and stability of optimized enzyme electrode were determined. Moreover, activation energy for enzymatic reaction was calculated. In conclusion, it was found that a concentration of 0.25 M pyrrole in the presence of 100U/ml of glucose oxidase in a 0.01 M KC1 solution, were the optimal parameters for the fabrication of the biosensor. The optimal response was obtained for film thickness of 0.777 jam at pH 7 and at a temperature of 308 K. The temperature dependence of the amperometric response indicated an activation energy of 13 kj/mole. The linearity of the enzyme electrode response ranged from 2.5 mM to 15 mM glucose. The specificity of the enzyme electrode was investigated for various substrates such as sucrose, ascorbic acid, succinic acid, maleic acid and no discrenible signal was detected above the background current. The shelf life and the operational stability of the enzyme electrodes under various storage conditions has been tested periodically.
Açıklama
Anahtar Kelimeler
Kimya, Chemistry
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Özden, M. (1994). Polipirol-glikoz oksidaz biyosensörün hazırlanması ve deneysel parametrelerin optimizasyonu.Yayımlanmış Yüksek lisans Tezi, İnönü Üniversitesi, Malatya.
