title: Electrochemical biosensor based on functional composite nanofibers for detection of K-ras gene via multiple signal amplification strategy.
abstract: An electrochemical biosensor based on functional composite nanofibers for hybridization detection of specific K-ras gene that is highly associated with colorectal cancer via multiple signal amplification strategy has been developed. The carboxylated multiwalled carbon nanotubes (MWCNTs) doped nylon 6 (PA6) composite nanofibers (MWCNTs-PA6) was prepared using electrospinning, which served as the nanosized backbone for thionine (TH) electropolymerization. The functional composite nanofibers [MWCNTs-PA6-PTH, where PTH is poly(thionine)] used as supporting scaffolds for single-stranded DNA1 (ssDNA1) immobilization can dramatically increase the amount of DNA attachment and the hybridization sensitivity. Through the hybridization reaction, a sandwich format of ssDNA1/K-ras gene/gold nanoparticle-labeled ssDNA2 (AuNPs-ssDNA2) was fabricated, and the AuNPs offered excellent electrochemical signal transduction. The signal amplification was further implemented by forming network-like thiocyanuric acid/gold nanoparticles (TA/AuNPs). A significant sensitivity enhancement was obtained; the detection limit was down to 30fM, and the discriminations were up to 54.3 and 51.9% between the K-ras gene and the one-base mismatched sequences including G/C and A/T mismatched bases, respectively. The amenability of this method to the analyses of K-ras gene from the SW480 colorectal cancer cell lysates was demonstrated. The results are basically consistent with those of the K-ras Kit (HRM: high-resolution melt). The method holds promise for the diagnosis and management of cancer.
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. Electronic address: wxy@seu.edu.cn.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory Medicine, Zhongda Hospital, Southeast University, Nanjing 210009, China.
authors.forename: Guofang
authors.initials: G
authors.lastname: Shu
authors.affiliation: Department of Oncology, Zhongda Hospital, Southeast University, Nanjing 210009, China.
authors.forename: Chanchan
authors.initials: C
authors.lastname: Gao
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Tang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000235:genetics; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D005784:Gene Amplification; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D057139:Nanofibers
keywords: Electrospinning; Functional composite nanofibers; K-ras gene; Sandwich format; Signal amplification