Nanoyapılı malzemelerin biyolojik moleküllerle entegrasyonu,karakterizasyonu ve uygulamaları

Nano boyutta yenilikçi biyomalzemelerin tasarlanması, özellikle biyouyumluluk ve biyobozunurluk gibi özelliklerin önem arz ettiği biyoteknolojik ve nanoteknolojik proseslerde en güncel araştırma konularından biridir. Diğer biyomalzemeler ile kıyaslandığında karbohidrat temelli polimer malzemeler; ulaşılabilirlik, maliyet ve fizikokimyasal özellikler açısından çok önemli avantajlar sağlar. Elektroeğirme tekniği, nano boyutlu karbohidrat temelli fiber sentezi için kolay ve gelecek vaad eden bir tekniktir. Bu çalışmada, selüloz türevi olan selüloz asetat (CA) polimeri kitosan (CS) polimeri ile karıştırılmış, elektroeğirme tekniği kullanılarak CA-CS nanofiberleri sentezlenmiştir. Nano boyutta, boncuk içermeyen CA-CS fiberlerin elde edilebilmesi için farklı çözgen sistemleri ve CA-CS oranları incelenmiş, işlem parametreleri optimize edilmiştir. Sentezlenen, CA-CS nanoliflerinin yüzey morfolojisini karakterize etmek için taramalı elektron mikroskobu kullanılmıştır. Daha sonra CA-CS nanofiberlerin, immobilizasyon materyali olarak uygunluğunun test edilmesi amacıyla; glukoz oksidaz enzimi CA-CS nanofiber kaplı GCE üzerine kovalent olarak immobilize edilmiş ve CA-CS/GOx biyosensörü hazırlanmıştır. İmmobilizasyonun başarısını kanıtlamak amacıyla CV, DPV, EIS teknikleri kullanılarak ölçümler alınmış ardından CA-CS/GOx biyosensörünün glukoza karşı cevabı amperometrik olarak incelenmiştir. CA-CS/GOx biyosensörlerinin dedeksiyon limiti ve glukoz doğrusal aralığı sırasıyla, 14 μM ve 5 µM-0,75 mM bulunmuştur. Son olarak CA-CS/GOx biyosensörünün gerçek örneklerde uygulanabilirliğinin araştırılması amacıyla, glukoz içeren sentetik örnekler ile ölçümler alınmıştır.Producing biomaterials in nanoscale architecture is one of the most popular topic as biological and nanotechnologic applications particularly relies on biocompatibility and biodegradability. Among other biomaterials, carbohydrate-based polymers satisfy the demand in terms of availability, cost-efficiency and physicochemical properties. Electrospinning is a promising and simple technique to produce carbohydrate-based nanofibers. In this study, one of the cellulose derivative cellulose acetate (CA) was blended with chitosan (CS) and CA-CS nanofibers were synthesized via electrospinning technique. Different solvent systems and CA-CS polymer ratio were examined and process parameters were optimized to obtain the ultrafine and bead-free CA-CS nanofibers. Scanning electron microscopy (SEM) was performed to characterize the surface morphology of CA-CS nanofibers. Then, to test the CA-CS nanofibers as an immobilization material; glucose oxidase (GOx) was immobilized on CA-CS coated GCE by covalent modification to design biosensor platform. CV, DPV, EIS measurements were carried out to prove the surface modification and CA-CS/GOx biosensor was tested for glucose detection by amperometric technique. Limit of detection (LOD) and linear response for glucose of CA-CS/GOx biosensor was found 14 μM and 5 µM-0,75 mM respectively. Finally, CA-CS/GOx platform was investigated to detect glucose in synthetic samples

High generation dendrimer decorated poly-?-caprolactone/polyacrylic acid electrospun nanofibers for the design of a bioelectrochemical sensing surface

WOS:000634154000001In this study, poly-?-caprolactone (PCL) and poly(acrylic) acid (PAA)-based electrospun nanofibers were prepared for the immobilization of pyranose oxidase (PyOx) to design a bioelectrochemical detection system. Different amounts of PAA were used to increase hydrophilicity (decreased contact angle) of the PCL electrospun nanofibers. To provide a multipoint attachment side to bind PyOx by covalent bonds, various amounts of high generation (G5) poly(amidoamine) (PAMAM) dendrimer with amino groups were added to the PCL:PAA backbone. To attach PyOx onto the PCL:PAA/PAMAM electrospun nanofibers, glutaraldehyde was used as a homobifunctional crosslinker. Firstly, PCL:PAA ratio was optimized to obtain the best electrospun nanofibers without beads and with decreased contact angle. Then, the effect of the PAMAM amount on the morphology of PCL:PAA and contact angle was tested. The obtained PCL:PAA/PAMAM electrospun nanofiber was characterized by scanning electron microscopy (SEM). Then, the presence of PAMAM in the structure and the success of PyOx immobilization onto PCL:PAA/PAMAM were proven by SEM and an energy dispersive X-ray analyzer (SEMEDX). Finally, PCL:PAA/PAMAM/PyOx was characterized, calibrated, and applied to analyze glucose in samples without any interfering effect of some chemicals. Briefly, the nanofibers modification with dendrimers and the conjugation of PyOx onto formed nanostructures was successfully performed, and a novel electrospun nanofiberbased sensor system was developed for target detection.BAGEP Award of the Science Academy; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [215Z194]; TUBITAK 2209Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)Acknowledgement This work is supported by the BAGEP Award of the Science Academy and TUBITAK (Project number: 215Z194) . A. Oner, E. Tufek, A. Birol and M. Demir thank to TUBITAK 2209 AProgram for the University Students at Undergraduate Level. Authors thank to Assoc. of Prof. Dr. Murat Yavuz for his valuable helps