Aflatoksin B1 ve Aflatoksin G1'in DNA Hibridizasyonuna Etkisinin Elektrokimyasal DNA Biyosensörü ile İncelenmesi

Biyomoleküler analizlerde yeni teknolojilerin gelişmesi, elektrokimyasal sensör alanındaki çalışmaların da katılmasıyla güncel bir konu olmuştur. Bu çalışmada Aflatoksin B1'in (AFB1) ve Aflatoksin G1'in (AFG1) DNA hibridizasyonu üzerindeki etkisi, kalem grafit elektrot (PGE) kullanılarak elektrokimyasal yöntemlerle analiz edildi. Bu amaçla; guanin oksidasyon akımlarındaki değişiklikler, diferansiyel puls voltametrisi (DPV) ile birbirlerini eşleniği olan DNA baz sekansları arasında hibridizasyon oluşmadan önce ve sonra izlendi. Çalışmanın ilk aşamasında, yakalama probu ıslak adsorpsiyonla PGE yüzeyine immobilize edilirken prob derişimi ve adsorpsiyon süresi optimize edildi ve sonra, hedef prop ile hibritleşmeye tabi tutulurken hedef proba ait konsantrasyon ve hibridizasyon süresi optimize edildi. İkinci aşamada, hibridizasyon deneyleri, birinci aşamada kullanılan yakalama probu yerine inosin modifiye edilmiş yakalama probu kullanılarak tekrarlandı. Ancak, ilk aşamadan farklı bir şekilde inosin modifiye edilmiş prob, hibridizasyona tabi tutulmadan önce 10 dakika süre ile 2 µg / mL ve 4 µg / mL AFB1 ile etkileştirildi ve aynı protokol, aynı koşullarda AFG1 için de tekrarlandı. Hibridizasyondan sonra guanin oksidasyon akımındaki azalma, aflatoksinlerin DNA sekanslarının hibridizasyonuna etkisinin bir sonucu olup, AFB1 ve AFGl'in DNA üzerine genotoksik etkisinin bir göstergesidir. Guanin oksidasyon sinyalindeki azalmalar 2 µg/mL ve 4 µg/mL AFG1 için % 18 ve % 26; 2 µg/mL ve 4 µg/mL AFB1 için % 50 ve % 61 olarak bulundu. Sonuç olarak AFB1'in DNA üzerindeki genotoksik etkisi AFG1'e göre çok daha fazla olarak tespit edildi.

Investigation of the effect of Aflatoxin B1 and Aflatoxin G1 on DNA Hybridization by Using Electrochemical DNA Biosensor

Biomolecular detection has become a current issue together with the increase in electrochemical sensor studies. The effect of Aflatoxin B1 and Aflatoxin G1 on DNA hybridization was analyzed with electrochemically by using pencil graphite electrode. For this purposes; the changes in guanine currents were monitored before and after hybridization occurred between DNA complementary base sequences using differential pulse voltammetry (DPV). In the first step of this work the capture probe was immobilized by wet adsorption onto the surface of PGE optimizing concentration and immobilization time and then hybridization event was performed between capture and its target probe. In the second step the hybridization experiments were repeated using inosine modified capture probe instead of capture probe which used in the first step. As differently from the first step the inosine modified probe was interacted with 2 µg/mL and 4 µg/mL of AFB1 for 10 min before allowing hybridization and the same protocol was repeated for AFG1. The decrease in guanine current after hybridization was the reference for the genotoxic effects of aflatoxins. The decrease in guanine oxidations in the cases of 2 µg/mL and 4 µg/mL AFG1 and 2 µg/mL and 4 µg/mL AFB1 concentrations were found to be 18% and 26 % for AFG1; and 50% and 61% for AFB1, respectively. AFB1 showed the maximum genotoxic effect to DNA hybridization.

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