Amiloid beta tayini için elektrokimyasal esaslı biyosensör sistemi geliştirilmesi
Yükleniyor...
Dosyalar
Tarih
2021
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Trakya Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Alzheimer hastalığı nöronların ölümüne sebep olan, ölümle sonuçlanan, geri dönüşümsüz bir demans türüdür. Hastalık, hiperfosforile tau proteini ile nörofibriler yumak oluşumu ve amiloid-beta (A?) proteini ile amiloid plakların oluşumuyla karakterize edilmektedir. Nörofibriler yumak oluşumu klinik belirtilerin ortaya çıkışı ile eş zamanlı iken amiloid plak oluşumu hastalığın ortaya çıkışından yaklaşık 20-30 yıl öncesinde başlayabilmektedir. Bu nedenle A?42 analizi Alzheimer hastalığında erken evrede teşhisin yolunu açabilir. Ayrıca hastalığa dair ilaç çalışmalarında ilaç etkinliğinin takibi için de A?42 ’nin kan plazması gibi vücut sıvılarında tespiti önem arz etmektedir. Bu tez kapsamında, Alzheimer hastalığında A?42 analizi için elektrokimyasal temelli impidimetrik bir biyosensör geliştirilmiştir. Bu biyosensörde maliyeti düşük ve tek kullanımlık indiyum kalay oksit polietilen teraftalat (ITO-PET) tabakalar çalışma elektrodu olarak kullanılmıştır. Biyosensör tasarımı, 3glisidoksipropildimetoksimetilsilan (GPDMMS) ile kendiliğinden oluşan tek tabakalar (SAMs) oluşturulduktan sonra A?42 proteinine özgü antikor immobilizasyonu ile yapılmıştır. Biyosensör ölçümleri elektrokimyasal impedans spektroskopisi ve döngüsel voltametri teknikleri ile yapılmıştır. Geliştirilen biyosensörün doğrusal tayin aralığının 1100 pg/ml konsantrasyon aralığında ve LOD değerinin 0.37 pg/ml ve LOQ değerinin 1.25 pg/ml olduğu tespit edilmiştir. Bu biyosensörün yaklaşık iki ay süreyle +4 o C’de depolanabildiği belirlenmiştir. Farklı analit proteinlere karşı seçiciliğini koruduğu tespit edilmiştir. Tek kullanımlık ve maliyeti düşük çalışma elektrotları rejenere edilerek biyosensör maliyetinin 6 kat daha azaltılabileceği gösterilmiştir. A?42 analizi için geliştirilen bir biyosensörde ilk kez sabit frekansta impedans (SFI) analizi yapılarak antikor-antijen kompleksi oluşumundaki kinetik davranış izlenmiştir. Yapay serum ve ticari olarak satın alınan insan serumunda A?42 analizi yapılarak geliştirilen biyosensörün klinik araştırmalarda kullanılmak üzere kanda analiz yapabilme kapasitesi olduğu gösterilmiştir.
Alzheimer's disease is an irreversible type of dementia that causes the death of neurons, resulting in death. The disease is characterized by the formation of neurofibrillary tangles by the hyperphosphorylated tau protein and the formation of amyloid plaques by the amyloid-beta (A?) protein. While neurofibrillary tangle formation is simultaneous with the onset of clinical symptoms, amyloid plaque formation may begin approximately 20-30 years before the onset of the disease. Therefore, A?42 analysis has the potential to be used for early diagnosis of Alzheimer's disease. In addition, detection of A?42 in body fluids such as blood plasma is important for monitoring drug efficacy in drug studies on the disease. In this thesis, an electrochemical based impidimetric biosensor was developed for A?42 analysis in Alzheimer's disease. In the construction of this biosensor, low cost and disposable indium tin oxide polyethylene terephthalate (ITO-PET) sheets were used as the working electrode. The biosensor design was made by the immobilization of A?42 protein-specific antibody after self-assembled monolayers (SAMs) were formed with 3glycidoxypropyldimethoxymethylsilane (GPDMMS) on the ITO-PET electrode surface. Biosensor responses were obtained by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. It was determined that the linear detection range of the developed biosensor was 1-100 pg/ml, and the LOD value was 0.37 pg/ml and the LOQ value was 1.25 pg/ml. It has been determined that this biosensor can be stored at +4 °C for about two months. It showed selectivity for A?42 protein when compared with different analyte proteins. It has been shown that the cost of biosensors can be reduced by 6 times by regenerating disposable and cost-effective working electrodes. The kinetic behavior in the formation of antibody-antigen complex was observed for the first time by performing single frequency impedance (SFI) analysis in a biosensor developed for A?42 analysis. It has been shown that the biosensor, which was developed by analyzing A?42 in artificial serum and commercially purchased human serum, has the capacity to be used for blood analysis in clinical studies.
Alzheimer's disease is an irreversible type of dementia that causes the death of neurons, resulting in death. The disease is characterized by the formation of neurofibrillary tangles by the hyperphosphorylated tau protein and the formation of amyloid plaques by the amyloid-beta (A?) protein. While neurofibrillary tangle formation is simultaneous with the onset of clinical symptoms, amyloid plaque formation may begin approximately 20-30 years before the onset of the disease. Therefore, A?42 analysis has the potential to be used for early diagnosis of Alzheimer's disease. In addition, detection of A?42 in body fluids such as blood plasma is important for monitoring drug efficacy in drug studies on the disease. In this thesis, an electrochemical based impidimetric biosensor was developed for A?42 analysis in Alzheimer's disease. In the construction of this biosensor, low cost and disposable indium tin oxide polyethylene terephthalate (ITO-PET) sheets were used as the working electrode. The biosensor design was made by the immobilization of A?42 protein-specific antibody after self-assembled monolayers (SAMs) were formed with 3glycidoxypropyldimethoxymethylsilane (GPDMMS) on the ITO-PET electrode surface. Biosensor responses were obtained by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. It was determined that the linear detection range of the developed biosensor was 1-100 pg/ml, and the LOD value was 0.37 pg/ml and the LOQ value was 1.25 pg/ml. It has been determined that this biosensor can be stored at +4 °C for about two months. It showed selectivity for A?42 protein when compared with different analyte proteins. It has been shown that the cost of biosensors can be reduced by 6 times by regenerating disposable and cost-effective working electrodes. The kinetic behavior in the formation of antibody-antigen complex was observed for the first time by performing single frequency impedance (SFI) analysis in a biosensor developed for A?42 analysis. It has been shown that the biosensor, which was developed by analyzing A?42 in artificial serum and commercially purchased human serum, has the capacity to be used for blood analysis in clinical studies.
Açıklama
Anahtar Kelimeler
Amiloid-beta (Aβ) Peptidi, Alzheimer Hastalığı Teşhisi, Elektrokimyasal Biyosensör, İmmünosensör, İmpidimetrik Biyosensör, Amyloid-beta (Aβ) peptide, Alzheimer’s Disease Diagnosis, Electrochemical Biosensor, Immunosensor, Impidimetric Biosensor
