Recent Development of Nano-Materials Used in DNA Biosensors

Abstract

As knowledge of the structure and function of nucleic acid molecules has increased, sequence-specific DNA detection has gained increased importance. DNA biosensors based on nucleic acid hybridization have been actively developed because of their specificity, speed, portability, and low cost. Recently, there has been considerable interest in using nano-materials for DNA biosensors. Because of their high surface-to-volume ratios and excellent biological compatibilities, nano-materials could be used to increase the amount of DNA immobilization; moreover, DNA bound to nano-materials can maintain its biological activity. Alternatively, signal amplification by labeling a targeted analyte with nano-materials has also been reported for DNA biosensors in many papers. This review summarizes the applications of various nano-materials for DNA biosensors during past five years. We found that nano-materials of small sizes were advantageous as substrates for DNA attachment or as labels for signal amplification; and use of two or more types of nano-materials in the biosensors could improve their overall quality and to overcome the deficiencies of the individual nano-components. Most current DNA biosensors require the use of polymerase chain reaction (PCR) in their protocols. However, further development of nano-materials with smaller size and/or with improved biological and chemical properties would substantially enhance the accuracy, selectivity and sensitivity of DNA biosensors. Thus, DNA biosensors without PCR amplification may become a reality in the foreseeable future.

Molecular Beacon Lighting up on Graphene Oxide

“…high pM to low nM). 1,[56][57][58] For our sensitivity test, the target DNA was complementary only to a portion of the 24-mer probe, leaving 9 unpaired nucleotides. If the full 24-mer was used, higher fluorescence intensity was achieved ( Figure 6D).…”

Nanomaterials as Promising DNA Biosensors

“…According to Xu et al [20] , Li and Hu [21] developed an electrochemical determination method for analyzing sequence -specifi c DNA using ferrocene -capped Au -NP/streptavidin conjugates. Thiolated DNA probes were covalently immobilized on a gold electrode with hexanethiol forming a mixed self -assembled monolayer and hybridized with target DNA containing a complementary sequence.…”

The increasing importance of carbon nanotubes and nanostructured conducting polymers in biosensors

“…By developing biosensors with improved sensitivity it will eliminate the need for PCR and thus simplify DNA biosensors. This can be achieved using nanomaterials which, due to their large surface area, allow a greater number of DNA strands to be immobilised (6). Nanomaterials can be incorporated into many types of biosensor configurations to develop magnetic, optical, electrical or electrochemical biodevices for the detection of many biological molecules including nucleic acids, antibodies, proteins, toxins and bacteria (7)(8)(9)(10)(11)(12)(13) The first biosensors were reported in the early 1960's, where a pH response for a 10 mg per cent solution of glucose was reported (14).…”