title: Signal enhancement of silicon nanowire-based biosensor for detection of matrix metalloproteinase-2 using DNA-Au nanoparticle complexes.
abstract: Silicon nanowires have been used in the development of ultrasensitive biosensors or chemical sensors, which is originated in its high surface-to-volume ratio and function as field-effect transistor (FET). In this study, we developed an ultrasensitive DNA-gold (Au) nanoparticle complex-modified silicon nanowire field effect transistor (SiNW-FET) biosensor to detect matrix metalloproteinase-2 (MMP-2), which has been of particular interest as protein biomarker because of its relation to several important human diseases, through an enzymatic cleavage reaction of a specific peptide sequence (IPVSLRSG). SiNW patterns with a width of 100 nm and height of 100 nm were fabricated on a p-type silicon-on-insulator (SOI) wafer by electron-beam lithography. Next, negatively charged DNA-Au nanoparticle complexes coupled with the specific peptide (KKGGGGGG-IPVSLRSG-EEEEEE) were applied on the SiNWs to create a more sensitive system, which was then bound to aldehyde-functionalized SiNW. The enhanced negatively charged nanoparticle complexes by attached DNA were used to enhance the conductance change of the p-SiNW by MMP-2 cleavage reaction of the specific peptide. MMP-2 was successfully measured within a range of 100 fM to 10 nM, and the conductance signal of the p-type SiNW by the MMP-2 cleavage reaction was enhanced over 10-fold by using the DNA-Au nanoparticle complexes compared with using SiNW-attached negative single peptide sequences.
authors.affiliation: Department of Chemical & Biomolecular Engineering, Sogang University , #1 Shinsu-dong, Mapo-gu, Seoul 121-742, Republic of Korea.
authors.forename: Jin-Ha
authors.initials: JH
authors.lastname: Choi
authors.forename: Han
authors.initials: H
authors.lastname: Kim
authors.forename: Jae-Hak
authors.initials: JH
authors.lastname: Choi
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Choi
authors.forename: Byung-Keun
authors.initials: BK
authors.lastname: Oh
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D053770:Nanowires / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D012825:Silicon / Q000737:chemistry*
chemical_list: D010455:Peptides; D006046:Gold; D004247:DNA; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D012825:Silicon