Facile fabrication of a silicon nanowire sensor by two size reduction steps for detection of alpha-fetoprotein biomarker of liver cancer

• Published in: Advances in natural sciences. Nanoscience and nanotechnology Vol. 6; no. 4; pp. 45001 - 6
• Main Authors: Pham, Van Binh, Pham, Xuan ThanhTung, Phan, Thanh Nhat Khoa, Le, Thi Thanh Tuyen, Dang, Mau Chien
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.12.2015
• Subjects: AFP detection; Biomarkers; biosensor; Biosensors; Cancer; Diagnosis; GPTS; Liver; liver cancer; Nanowires; Sensors; Silicon; silicon nanowire; surface modification
• ISSN: 2043-6262; 2043-6254; 2043-6254; 2043-6262
• DOI: 10.1088/2043-6262/6/4/045001

We present a facile technique that only uses conventional micro-techniques and two size-reduction steps to fabricate wafer-scale silicon nanowire (SiNW) with widths of 200 nm. Initially, conventional lithography was used to pattern SiNW with 2 m width. Then the nanowire width was decreased to 200 nm by two size-reduction steps with isotropic wet etching. The fabricated SiNW was further investigated when used with nanowire field-effect sensors. The electrical characteristics of the fabricated SiNW devices were characterized and pH sensitivity was investigated. Then a simple and effective surface modification process was carried out to modify SiNW for subsequent binding of a desired receptor. The complete SiNW-based biosensor was then used to detect alpha-fetoprotein (AFP), one of the medically approved biomarkers for liver cancer diagnosis. Electrical measurements showed that the developed SiNW biosensor could detect AFP with concentrations of about 100 ng mL−1. This concentration is lower than the necessary AFP concentration for liver cancer diagnosis.