A Nano-Biosensor for Label-Free Detection of Nucleic Acid Using Silicon Nano-Structured Materials

Abstract

The development of biosensors for the detection of biological molecules has been subject to an intensive research. Nucleic acid detection of both deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) has been the most accurate technique used to date for diseases diagnosis and research purposes. Here, we are presenting a silicon-based nanobiosensor for label-free detection of nucleic acids using aptamers-adsorbed nanostructures such as silicon nanowires (SiNWs). The detector consists of nano-structured materials and will be placed within, a microfluidic embodiment. The application of nano-photonics principles allows for detecting changes in absorption when there is a minute change in the surroundings of the nanostructured material. Using previously developed protocols to fabricate the nanostructured materials with various geometries, and functionalize them with nucleic acid aptamers, we investigated and developed novel structures of solid and hollow silicon nanowires with light absorption that is sensitive to changes in the surrounding molecules. The nanostructured material is first coated by immobilized aptamer, and absorption is measured. A change in absorption occurs when the target nucleic acid fragments hybridize with its complementary immobilized aptamer on the nanostructured material. The nano-biosensor presented here is a novel device with applications in disease diagnostic as well as drug discoveries, as it is an accurate, affordable, rapid and easy-to-use in both clinical and research settings.