DNA Hybridization on Membrane‐Modified Carbon Electrodes

Abstract

The DNA-modified membrane electrode was prepared by casting a mixture of nitrocellulose (NC) with target DNA (tDNA) in organic solvent on glassy carbon electrode (GCE). Unlabeled polymerase chain reaction (PCR)-amplified human genomic sequence (628 bp) or synthetic oligodeoxynucleotides (ODNs) were used as tDNAs, creating a recognition layer. Biotinylated ODNs were used as hybridization probes to recognize specific nucleotide sequences. The hybridization events were detected via an enzyme-linked electrochemical assay involving binding of streptavidincoupled alkaline phosphatase (SALP) to the biotin labels of the probe bound to tDNA. After the probe hybridization and SALP binding, the electrode was immersed into an electroinactive enzyme substrate (1-naphthyl phosphate). The alkaline phosphatase converted the inactive substrate into electroactive 1-naphthol that penetrated through the NC membrane to the GCE surface and was subsequently detected using an anodic voltammetric signal. The optimized method offered a good discrimination between complementary and nonspecific DNAs and yielded well-defined responses for both single-copy and repetitive tDNA sequences. In contrast to previously published methods using electrodes with mechanically attached membranes, the previously mentioned electrode is easily amenable to parallel DNA analysis.

Easy to use and rapid isolation and detection of a viral nucleic acid by using paramagnetic microparticles and carbon nanotubes-based screen-printed electrodes

“…Oligonucleotide probe with specific viral-complementary sequence was labeled by biotin on 5 0 tail. The vitamin (biotin) has a very high affinity to avidin/streptavidin (dissociation constant of 10 -15 M), and this interaction has been utilized in many types of avidinbiotin technologies (Kizek et al 2005;Kourilova et al 2005;Masarik et al 2003;Petrlova et al 2007a, b). If paramagnetic microparticles are covered with streptavidin, they are able to bind oligonucleotide chains labeled with biotin.…”

“…However, the labeling of specific nucleic acids sequences is hardly to be done on site. Therefore, many scientists focus on direct nucleic acid detection (Jelen et al 2004;Kourilova et al 2005;Palecek 2002;Palecek et al 2002a). Techniques based on simple and easy-to-use biological sample processing such as paramagnetic particles play an important role in this area (Palecek and Fojta 2007;Palecek et al 2002b) as well as attempts to miniaturize a whole detection system e.g., screen-printed electrodes, which can be modified with various types of nano-materials (Huska et al 2008b;Kumar and Chen 2008;Wang and Musameh 2004).…”

Escherichia coli Genosensor Based on Polyaniline

“…Electrochemical transducers have been considered as a simple and sensitive method of DNA hybridization detection. − A wide range of conducting/semiconducting biomaterials including carbon paste, gold, screen-printed electrodes, self-assembled monolayers, and conducting polymers have been utilized for development of genosensors (DNA electrochemical biosensors). Electrochemical DNA biosensors have been reported to detect complementary sequences of HIV DNA, A. ostenfeldii , C. parvum , Microcystis sp., etc.…”

Disposable Electrochemical Biosensor with Multiwalled Carbon Nanotubes-Chitosan Composite Layer for the Detection of Deep DNA Damage

“…A special group of polymers for biosensing is represented by polysaccharide matrices. 3 Chitosan (CHIT) is a polysaccharide biopolymer with Nacetylglucosamine and glucosamine units (Fig. 1).…”