Mimetik Biyomoleküller Kullanılarak Metamalzeme Yüzeyinin Geliştirilmesi ve Meta-Biyo-Sensör Hazırlanması

Abstract

In the scope of this thesis, the potential use of metamaterials, which have outstanding features at nano scales as an efficient transducer was presented. For this purpose, two different metamaterials such as Split Ring resonator (SRR) and Indium Tin-oxide Nanorod (ITO NR) have been studied. With the results of the simulation, a structure with a maximum sensitivity to a desired wavelength has been determined. Nano metamaterial surfaces have been nanofabricated by using electron beam lithography. These surfaces have been characterized on the basis of Fourier transform infrared spectroscopy (FTIR-ATR), atomic force microscopy (AFM), scanning electron microscopy (SEM) and optical transmittance. Because of the chemical stability gold has been used as a fundamental material for the preparation of transducer related to the meta-bio-sensor. Quartz with high optical transmission properties has been used as a substrate in the preparation of chip samples. The aim of this work is to design a refractive index sensor which is highly-sensitive, works at near infrared region and built on metatronic nano-circuits. The sensor is fabricated by arranging the transparent conducting oxides in a nano-rod geometry. The functionality of these polarization dependent metatronic nano-circuits is enhanced by bringing in a tunable response. This feature is investigated by depositing NH¬2 (Amine) groups via plasma polymerization technique on top of indium-tin-oxide (ITO) nano-rods. For surface functionalization, amine functional group (-NH2) which is enable the binding of peptide molecules to the surface has been added via plasma polymerization method at different plasma conditions (power/time). Recognition layers have been created with Antimicrobial Peptide Mimetics (AMPm) oligo [acyl-lysine] (OAK) and Thrombin Aptamers in order to make transducer target specific. In the last stage, Meta-bio- sensors produced like this have been tested against the target analyte and the responses of the sensor have been evaluated. In the nano-sensor system prepared by AMPm surface modification, meaningful response was obtained with 15 min. analysis period against to 102 cfu / ml E. coli target concentration. In the nano-sensor system prepared by aptamer surface modification, meaningful response was obtained with 15 min. analysis period against to 120 mM target concentration. Regeneration of both nano-biosensors has been demonstrated in this study. Both sensor surfaces showed selective behavior against their targets and weren’t responded to false positives. The aim of this thesis is to create a biosensor with high sensitivity, selectivity and accuracy with the integration of AMPm and Aptamers with metamerials. This study has two objectives; the first is to provide a sensitive biosensor that allows single cell diagnosis, and the second is to provide a cheap and highly sensitive biosensor that will allow measurement at the picomolar level. Biosensor studies with these ITO NRs are thought to be the basis for obtaining precise and biocompatible metatronic nano-structures that can be implanted in the body to obtain nanophotonic biosensors for individual medical applications in the near future. Meta-biosensor with advanced properties, which have been modified with AMPm and Aptamers and PlzP surface modification, will be the first in the literature. Within the scope of the thesis, a new system has been put into practice with the preparation, modification and application of nano-surfaces and these new meta-biosensors have been successfully developed.