In this contribution, an electrochemical aptameric sensing scheme for the sensitive detection of small molecules is proposed using adenosine as a target model. A ferrocene (Fc)-functionalized thiolated aptamer probe is adapted and immobilized onto an electrode surface. Introducing a recognition site for EcoRI into the aptamer sequence not only suppresses the peak current corresponding to blank ...

The G-quadruplex architecture is a peculiar structure adopted by guanine-rich oligonucleotidic sequences, and, in particular, by several aptamers, including the thrombin-binding aptamer (TBA) that has the highest inhibitory activity against human α-thrombin. A crucial role in determining structure, stability and biological properties of G-quadruplexes is played by ions. In the case of TBA, K(+)...

Affinity reagent pairs that recognize distinct epitopes on a target protein can greatly improve the sensitivity and specificity of molecular detection. Importantly, such pairs can be conjugated to generate reagents that achieve two-site "bidentate" target recognition, with affinities greatly exceeding either monovalent component. DNA aptamers are especially well-suited for such constructs, beca...

Human noroviruses (HuNoV) are the leading cause of acute viral gastroenteritis and an important cause of foodborne disease. Despite their public health significance, routine detection of HuNoV in community settings, or food and environmental samples, is limited, and there is a need to develop alternative HuNoV diagnostic reagents to complement existing ones. The purpose of this study was to sel...

hepatitis c virus (hcv) encodes two envelope glycoproteins, e1 and e2. our previous work selected a specific aptamer ze2, which could bind to e2 with high affinity, with a great potential for developing new molecular probes as an early diagnostic reagents or therapeutic drugs targeting hcv. in this study, the binding sites between e2 and aptamer ze2 were further explored. e2 was truncated to 15...

recently, specific attention has been paid to aptamers, short dna or rna, as a tool for cancer diagnosis and therapy. in the present study mcs nanogels were prepared by myristate: chitosan at 1:9 ratio and were characterized by several techniques. a selected ssdna aptamer(apt) capable of detecting lncap cells was linked to myristilated chitosan nanogels (apt-mcs) by glutaraldehyde and loaded wi...

We describe herein the development of a high affinity and specific DNA aptamer as a new ligand for use in liposomal nanoparticles to target cultured mouse tumor endothelial cells (mTECs). Active targeted nanotechnology based drug delivery systems are currently of great interest, due to their potential for reducing side effects and facilitating the delivery of cytotoxic drugs or genes in a site ...

Aptamer-based fluorescence anisotropy (FA) assay combines the advantages of affinity aptamers in good stability, easy generation, and facile labeling and the benefits of FA in homogeneous analysis, such as robustness, simplicity, and high reproducibility. By using a fluorophore-labeled aptamer, FA detection of a small molecule is not as easy as detection of protein because the binding of a smal...

Combining gold nanoparticles (GNPs) as fluorescence quencher and aptamer as probe, we have developed protein biosensors by using DNA-modified GNPs. We examined how the experimental design, such as the type of interaction between DNA strands and GNPs, temperature, and microenvironment of aptamer, influences the recognition ability of the biosensor. Under our experimental conditions, the recognit...

A peroxidase-active hemin-aptamer was clicked onto an immunoglobulin E (IgE) binding aptamer. The resulting bifunctional aptamer was successfully used in a highly sensitive aptazyme-linked oligonucleotide assay (ALONA) for the detection of IgE. The sensitivity of the assay is enhanced by isothermal amplification of the aptazyme followed by colorimetric detection of the aptazyme's peroxidase act...