Silicon nanowire (SiNW) electrical biosensing shows promise for point-of-care test (POCT) applications which can lead to more rapid cancer diagnosis and early intervention. Our goal is to increase the sensitivity of SiNW-based sensors through novel design and fabrication. We will utilize the superlattice nanowire pattern transfer (SNAP) method to produce highly aligned arrays of SiNWs, each 25 nm wide and 3 mm long. NW doping level will be optimized and sectioned into several individual sensor arrays, electrical contacts to the NW sensors established, and each array integrated into a microfluidic channel to demonstrate that a single-stranded complementary oligonucleotide on counter electrode is able to significantly change the conductance of a SiNWs in saline solution when hybridized to a primary DNA strand. Proof of principle will be demonstrated by the reproducible detection of target species, K-ras mutated DNA sequences spiked in saline. Sensitivity and specificity as well as reliability testing will be performed. For sensitivity testing, 25 samples with and 25 without spiked target DNA sequence will be tested and interpreted. For specificity, 25 non-target DNA sequence sample will be tested. For reliability testing, target DNA spiked samples will be retested twice and at 24-hour intervals and reliability coefficients calculated.
NIH Spending Category: Bioengineering; Cancer; Nanotechnology
Project Terms: Back; base; Bedside Testings; Binding (Molecular Function); Biosensing Techniques; cancer diagnosis; Characteristics; design; Detection; Devices; DNA; DNA Sequence; Early treatment; Electric Capacitance; Electrodes; Electron Microscope; Goals; Hour; Image; Individual; Lead; Measurement; Measures; Metals; Methods; Microfluidics; Mutate; nanofabrication; nanowire; novel; Nucleic Acids; Oligonucleotides; Pattern; Performance; Research; research study; response; Saline; Sampling; Scanning; Sensitivity and Specificity; sensor; Silicon; Specificity; Surface; Testing; Time; voltage; Width; Work
