Electronic biosensors offer a viable alternative to optical biosensors for the rapid, specific, and sensitive detection of DNA. We are utilizing an electrolyte-oxide-semiconductor (EOS) biosensor system on a SiO2/Si surface for impedimetric detection of DNA. Detection in this system is based on the intrinsic negative charge of DNA. Hybridization of target DNA to the probe-functionalized semicon...

We have prepared a novel optical fiber evanescent wave DNA biosensor using a newly developed molecular beacon DNA probe. The molecular beacons (MB) are oligonucleotide probes that become fluorescent upon hybridization with target DNA/RNA molecules. Biotinylated MBs have been designed and immobilized on an optical fiber core surface via biotin-avidin or biotin-streptavidin interactions. The DNA ...

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...

Single-stranded DNA (ssDNA) is a product of many cellular processes that involve double-stranded DNA, for example during DNA replication and repair, and is formed transiently in many others. Measurement of ssDNA formation is fundamental for understanding many such processes. The availability of a fluorescent biosensor for the determination of single-stranded DNA provides an important route to a...

For the diagnosis and prevention of diseases, a range of strategies for the detection of pathogens have been developed. In this study, we synthesized the rolling circle amplification (RCA)-based biosensor that enables detection of pathogen DNA in two analytical modes. Only in the presence of the target DNA, the template DNA can be continuously polymerized by simply carrying out RCA, which gives...

A redox active and electrochemiluminescent (ECL) threading bis-intercalator, consisting of two N,N'-bis(3-propyl-imidazole)-1,4,5,8-naphthalene diimides (PIND) linked by a Ru(dmbpy)2(2+) (dmbpy = 4,4'-dimethyl-2,2'-bipyridine) complex (PIND-Ru-PIND), was synthesized for the first time. Its optical, electrochemical, and ECL properties were studied. UV-vis spectrophotometric measurements indicate...

A nanoporous alumina membrane-based ultrasensitive DNA biosensor is constructed using 5'-aminated DNA probes immobilized onto the alumina channel walls. Alumina nanoporous membrane-like structure is carved over platinum wire electrode of 76 µm diameter dimension by electrochemical anodization. The hybridization of complementary target DNA with probe DNA molecules attached inside the pores influ...

Objective: The annual incidence of cancer in the world is growing rapidly. The most important factor in the cure of cancers is their early diagnosis. miRNA, as a biomarker for early detection of cancer, has attracted a lot of attention. Methods: In this study, an electrochemical biosensor was developed to detect the amount of miR-106a, the biomarker of gastric cancer, by modifying a glass...

Simple and convenient assays with quantum dots (QDs) as the labels for DNA detection are developed. The probe DNA modified with thiol was first immobilized on a pretreated Au electrode, and then the complementary DNA (cDNA) oligonucleotides were hybridized with the immobilized probes by immersing the probe-modified Au electrode into the cDNA oligonucleotide solution. Finally, the avidin-modifie...