title: Label-Free Direct Detection of miRNAs with Poly-Silicon Nanowire Biosensors.
abstract: BACKGROUND
  The diagnostic and prognostic value of microRNAs (miRNAs) in a variety of diseases is promising. The novel silicon nanowire (SiNW) biosensors have advantages in molecular detection because of their high sensitivity and fast response. In this study, poly-crystalline silicon nanowire field-effect transistor (poly-SiNW FET) device was developed to achieve specific and ultrasensitive detection of miRNAs without labeling and amplification.
  
  
  METHODS
  The poly-SiNW FET was fabricated by a top-down Complementary Metal Oxide Semiconductor (CMOS) wafer fabrication based technique. Single strand DNA (ssDNA) probe was bind to the surface of the poly-SiNW device which was silanated and aldehyde-modified. By comparing the difference of resistance value before and after ssDNA and miRNA hybridization, poly-SiNW device can be used to detect standard and real miRNA samples.
  
  
  RESULTS
  Poly-SiNW device with different structures (different line width and different pitch) was applied to detect standard Let-7b sample with a detection limitation of 1 fM. One-base mismatched sequence could be distinguished meanwhile. Furthermore, these poly-SiNW arrays can detect snRNA U6 in total RNA samples extracted from HepG2 cells with a detection limitation of 0.2 μg/mL. In general, structures with pitch showed better results than those without pitch in detection of both Let-7b and snRNA U6. Moreover, structures with smaller pitch showed better detection efficacy.
  
  
  CONCLUSIONS
  Our findings suggest that poly-SiNW arrays could detect standard and real miRNA sample without labeling or amplification. Poly-SiNW biosensor device is promising for miRNA detection.
authors.affiliation: School of Life Science, East China Normal University, Shanghai, PR China.|Ocean Research Center of Zhoushan, Zhejiang University, Zhejiang Province, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: He
authors.affiliation: Shanghai Integrated Circuit Research & Development Center, Shanghai, PR China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Zhu
authors.affiliation: School of Life Science, East China Normal University, Shanghai, PR China.
authors.forename: Changguo
authors.initials: C
authors.lastname: Gong
authors.affiliation: Shanghai Integrated Circuit Research & Development Center, Shanghai, PR China.
authors.forename: Jiming
authors.initials: J
authors.lastname: Qi
authors.affiliation: Wuhan Medical and Health Center for Women and Children, Wuhan, Hubei Province, PR China.
authors.forename: Han
authors.initials: H
authors.lastname: Xiao
authors.affiliation: Shanghai Integrated Circuit Research & Development Center, Shanghai, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.affiliation: School of Life Science, East China Normal University, Shanghai, PR China.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D045744:Cell Line, Tumor; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D053770:Nanowires / Q000737:chemistry*; D012342:RNA, Small Nuclear / Q000235:genetics*; D012825:Silicon / Q000737:chemistry*; D014173:Transistors, Electronic
chemical_list: D004277:DNA, Single-Stranded; D035683:MicroRNAs; D012342:RNA, Small Nuclear; C405486:U6 small nuclear RNA; C487931:mirnlet7 microRNA, human; D012825:Silicon