Microarrays of biomolecules hold great promise in the fields of genomics, proteomics, and clinical assays on account of their remarkably parallel and high-throughput assay capability. However, the fluorescence detection used in most conventional DNA microarrays is still limited by sensitivity. In this study, we have demonstrated a novel universal and highly sensitive platform for fluorescent detection of sequence specific DNA at the femtomolar level by combining dextran-coated microarrays with hybridization chain reaction (HCR) signal amplification. Three-dimensional dextran matrix was covalently coated on glass surface as the scaffold to immobilize DNA recognition probes to increase the surface binding capacity and accessibility. DNA nanowire tentacles were formed on the matrix surface for efficient signal amplification by capturing multiple fluorescent molecules in a highly ordered way. By quantifying microscopic fluorescent signals, the synergetic effects of dextran and HCR greatly improved sensitivity of DNA microarrays, with a detection limit of 10 fM (1 x 10(5) molecules). This detection assay could recognize one-base mismatch with fluorescence signals dropped down to 20%. This cost-effective microarray platform also worked well with samples in serum and thus shows great potential for clinical diagnosis. (C) 2016 Elsevier B.V. All rights reserved.
[1]Nanjing Univ Posts & Telecommun, IAM, KLOEID, 9 Wenyuan Rd, Nanjing 210046, Jiangsu, Peoples R China;
[2]Nanjing Univ Posts & Telecommun, Sch Mat Sci & Engn, 9 Wenyuan Rd, Nanjing 210046, Jiangsu, Peoples R China;
[3]Chinese Acad Sci, Shanghai Inst Appl Phys, Shanghai Synchrotron Radiat Facil, Div Phys Biol, 2019 Jialuo Rd, Shanghai 201800, Peoples R China;
[4]Chinese Acad Sci, Shanghai Inst Appl Phys, Shanghai Synchrotron Radiat Facil, Bioimaging Ctr, 2019 Jialuo Rd, Shanghai 201800, Peoples R China;
[5]Zhongshan Hosp, Pulm Medcine Dept, 180 Fenglin Rd, Shanghai 200032, Peoples R China
(8.0+极速模式)