A novel molecular aptamer beacon (MAB) was designed by integrating a single-labeled hairpin-shaped aptamer and graphene oxide (GO). The hairpin-shaped aptamer was constructed with anti-ATP aptamer and another five nucleotides added to the 5'-end of the aptamer which are complementary to nucleotides at the 3'-end of the aptamer to form a hairpin-shaped probe. This newly designed MAB which acts a...

RNA aptamers that bind HIV-1 reverse transcriptase (RT) inhibit HIV-1 replication, but little is known about potential aptamer-specific viral resistance. During replication, RT interacts with diverse nucleic acids. Thus, the genetic threshold for eliciting resistance may be high for aptamers that make numerous contacts with RT. To evaluate the impact of RT-aptamer binding specificity on replica...

We demonstrate for the first time, the development of titanium dioxide nanoparticles (TiO₂) quenching based aptasensing platform for detection of target molecules. TiO₂ quench the fluorescence of FAM-labeled aptamer (fluorescein labeled aptamer) upon the non-covalent adsorption of fluorescent labeled aptamer on TiO₂ surface. When OTA interacts with the aptamer, it induced aptamer G-quadruplex c...

Live cell RNA imaging using genetically encoded fluorescent labels is an important tool for monitoring RNA activities. A recently reported RNA aptamer-fluorogen system, the Spinach, in which an RNA aptamer binds and induces the fluorescence of a GFP-like 3,5-difluoro-4-hydroxybenzylidene imidazolinone (DFHBI) ligand, can be readily tagged to the RNA of interest. Although the aptamer-fluorogen s...

We report the picosecond and nanosecond timescale rotational dynamics of a dye-labeled DNA oligonucleotide or "aptamer" designed to bind specifically to immunoglobulin E. Rotational dynamics in combination with fluorescence lifetime measurements provide information about dye-DNA interactions. Comparison of Texas Red (TR), fluorescein, and tetramethylrhodamine (TAMRA)-labeled aptamers reveals su...

Aptamers are nucleic acids that can bind to various molecules. Because they have some features that are lacking in antibodies, aptamers could serve as alternatives to antibodies. For the purpose of biosensing, we focused on aptamers that undergo structural changes on binding to their target molecules. We constructed an aptamer-based bound/free (B/F) separation system that uses a designed aptame...

iv CHAPTER 1. GENERAL INTRODUCTION 1 Current reporter genes 1 Fluorescent proteins 3 In Vivo Imaging 6 RNA Imaging 8 Aptamers 9 Aptamer structure and stabilization 10 Applications of aptamers 11 Riboswitches natural RNAs with aptamer-like properties 12 Application of aptamers for imaging 13 Sulforhodamine-B and fluorescein aptamers 13 Fluorescence switches and “Light-up” aptamers 14 Theophyllin...

Aptamer-based assays represent a modern and attractive approach in bioanalytical chemistry. The DNA thrombin aptamer has been extensively investigated, and the coupling of this aptamer to different transduction principles has demonstrated the wide applicability of aptamers as bioreceptors in bioanalytical assays. The goal of this work was to critically evaluate all the parameters that can influ...

Anticoagulants are a vital class of drugs, which are applied for short-term surgical procedures, and for long-term treatments for thrombosis prevention in high risk groups. Several anticoagulant drugs are commercially available, but all have intrinsic disadvantages, e.g., bleeding risks, as well as specific ones, e.g., immune response to peptide/protein drugs. Therefore, the search for novel, e...

A bifunctional derivative of the thrombin-binding aptamer with a redox-active Fc moiety and a thiol group at the termini of the aptamer strand was synthesized. The ferrocene-labeled aptamer thiol was self-assembled through S-Au bonding on a polycrystalline gold electrode surface and the surface was blocked with 2-mercaptoethanol to form a mixed monolayer. By use of a fluorescent molecular beaco...