This STTR Phase I research proposal will demonstrate the feasibility of a nanoscale needle (nano-needle) probe biosensor assaying low-abundance nucleic acids without target-/signal amplification. The unique point in the proposed work lies in the combined use of dielectrophoresis and capillary action to fabricate a high-aspect ratio nano-needle made of a hybrid nanomaterial and to operate the nano-needle as a biosensor, achieving high sensitivity through size-exclusive sample concentration. The company has already succeeded in nonspecifically sampling/assaying intercalator-treated lambda-DNA spiked into a buffer or cell solution in a quantitative manner. The sensitivity of this achievement was around 10pg/mL (0.3fM) which is comparable to the concentration of naturally occurring DNA species and sufficient for screening/detection of circulating DNA in blood (sub-50ng/mL).
The method will pave the way to high throughput fabrication of high aspect ratio nano-needle structures and the application to the biosensing platform. The proposed nano-needle biosensor device will enable simple, rapid, yet sensitive detection without target-/signal amplification and minimize the operation in terms of the physical size, corresponding energy consumption, sample size, and sample preparation time as a field-deployable device. The biosensor is aimed for point-of-care-testing using minimally treated or raw samples. Eventually, the device will be applicable to nucleic acid testing (NAT) for rapid screening of diseases (e.g. cancer), which is enabled through minimally treated samples.
