Title: Improving gold nanowire-based biosensor sensitivity by changing probe design

Authors: Cao Huu Tien; Ha Van Linh; Pham Xuan Thanh Tung; Le Van Hieu

Addresses: Department of Magnetic and Biomedical Materials, University of Science, Vietnam National University-Ho Chi Minh City, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam ' Department of Magnetic and Biomedical Materials, University of Science, Vietnam National University-Ho Chi Minh City, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam ' Laboratory for Nanotechnology, Vietnam National University-Ho Chi Minh City, Community 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam ' Department of Magnetic and Biomedical Materials, University of Science, Vietnam National University-Ho Chi Minh City, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam

Abstract: To improve the sensitivity of the electrochemical DNA (E-DNA) sensors is extremely necessary for the diagnosis and early detection of cancer. Among the factors that affect the sensitivity of the sensors, the most important is the structure of the probe on the electrode surface. Probes may have different structures, but have only two detection mechanisms, that is signal-off and signal-on. Many reports suggest that the detection effect of signal-on probe is better than signal-off probe. To verify this, we have conducted experiments on two probes that have similar sequences which are complementary with target and typical for two detection mechanisms of the sensor, i.e., probe has stem-loop structure according to the signal-off mechanism, and probe has hairpin structure according to the signal-on mechanism in the same experimental conditions. The results showed that the limit of detection (LOD) of sensor with stem-loop probe is 200pM, meanwhile hairpin probe sensor has LOD of 25 pM.

Keywords: E-DNA sensor; stem-loop probe; hairpin probe; interleukin-8 mRNA; oral cancer.

DOI: 10.1504/IJNT.2018.089568

International Journal of Nanotechnology, 2018 Vol.15 No.1/2/3, pp.199 - 209

Available online: 30 Jan 2018 *

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