title: Silicon nanowire arrays for label-free detection of DNA.
abstract: Arrays of highly ordered n-type silicon nanowires (SiNW) are fabricated using complementary metal-oxide semiconductor (CMOS) compatible technology, and their applications in biosensors are investigated. Peptide nucleic acid (PNA) capture probe-functionalized SiNW arrays show a concentration-dependent resistance change upon hybridization to complementary target DNA that is linear over a large dynamic range with a detection limit of 10 fM. As with other SiNW biosensing devices, the sensing mechanism can be understood in terms of the change in charge density at the SiNW surface after hybridization, the so-called "field effect". The SiNW array biosensor discriminates satisfactorily against mismatched target DNA. It is also able to monitor directly the DNA hybridization event in situ and in real time. The SiNW array biosensor described here is ultrasensitive, non-radioactive, and more importantly, label-free, and is of particular importance to the development of gene expression profiling tools and point-of-care applications.
authors.affiliation: Institute of Microelectronics, 11 Science Park Road, Singapore 117685, Republic of Singapore. gaozq@ime.a-star.edu.sg
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Gao
authors.forename: Ajay
authors.initials: A
authors.lastname: Agarwal
authors.forename: Alastair D
authors.initials: AD
authors.lastname: Trigg
authors.forename: Navab
authors.initials: N
authors.lastname: Singh
authors.forename: Cheng
authors.initials: C
authors.lastname: Fang
authors.forename: Chih-Hang
authors.initials: CH
authors.lastname: Tung
authors.forename: Yi
authors.initials: Y
authors.lastname: Fan
authors.forename: Kavitha D
authors.initials: KD
authors.lastname: Buddharaju
authors.forename: Jinming
authors.initials: J
authors.lastname: Kong
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000032:analysis*; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D053770:Nanowires / Q000737:chemistry*; D012666:Semiconductors; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D004247:DNA; D012825:Silicon