Here we present a DNA module platform for developing simple aptamer sensors based on a microarray format combined with secondary structure prediction in silico. The platform comprises four parts: (i) aptamer, (ii) joint module, (iii) terminal stem, and (iv) a DNAzyme that catalyzes a redox reaction controlled by a structural change induced by aptamer/target binding. First, we developed a joint ...

Aptamer-based electrochemical sensors are now developed for the detection of a wide variety analytes including ions, low-molecular-weight molecules, proteins, and living cells. An aptamer-based sensor is an analytical device whose bio-sensing element (i.e. aptamer) immobilized on transducer surface. Aptasensors have attracted great attention because their high selectivity, sensitivity, stabilit...

The combination of specific ligand-binding aptamers with hairpin ribozyme catalysis generates molecules that can be controlled by external factors. Here we have generated hairpin ribozymes that can be regulated by a short DNA aptamer specific for human α-thrombin. This was achieved by constructing a ribozyme variant harboring an RNA sequence complementary to the aptamer, to which the aptamer ca...

We report here the in vitro selection of DNA aptamers for electric eel acetylcholinesterase (AChE). One selected aptamer sequence (R15/19) has a high affinity towards the enzyme (Kd=157±42 pM). Characterization of the aptamer showed its binding is not affected by low ionic strength (~20 mM), however significant reduction in affinity occurred at high ionic strength (~1.2 M). In addition, this ap...

To overcome early cancer detection challenges, diagnostic tools enabling more sensitive, rapid, and noninvasive are necessary. An attractive target for blood tests is human Ecto-NOX disulfide–thiol exchanger 2 (ENOX2), expressed in most types regularly shed into sera. Here, we developed an electrochemical DNA-based (E-DNA) biosensor that rapidly detects physiologically relevant levels of ENOX2....

We describe a general strategy for electronic aptamer-based biosensor that is based on target-induced strand release (TISR) of a redox-modified aptamer from the aptamer-capture DNA duplex bound on an electrode.

Enzyme replacement therapy for lysosomal storage diseases is currently based on endocytosis of lysosomal enzymes via the mannose or mannose 6-phosphate receptors. We are developing a technology for endocytosis of lysosomal enzymes that depends on generic, chemically conjugated reagents. These reagents are aptamers (single-stranded nucleic acid molecules) selected to bind to the extracellular do...

A universal aptamer-based sensing strategy is proposed using DNA modified nanocarriers and Resistive Pulse Sensing (RPS) for the rapid (≤20 min) label free detection of small molecules. The surface a magnetic nanocarrier was first with ssDNA (anchor) which designed to be partially complimentary in sequence aptamer. aptamer anchor form stable dsDNA complex on surface. Upon addition target molecu...

A novel method to quantitatively measure the binding of proteins to single-stranded DNA (ssDNA) aptamers that employs the inhibition of the DNAzyme hydrolysis of aptamer monolayers is described. A 28-base DNAzyme was designed to specifically bind to and cleave a 29-base ssDNA sequence that can fold into a G-quartet aptamer and bind the protein thrombin. The binding strength of the DNAzyme to th...

The electrochemical detection of interactions between aptamers and low-molecular-weight targets often lacks sensitivity. Signal amplification improves the detection of the aptamer-analyte complex; Bsm DNA polymerase was used to amplify the signal from the interaction of vanillin and its aptamer named Van_74 on an ion-sensitive field-effect transistor (ISFET)-based biosensor. The aptamer was imm...