Hybridization chain reaction amplification for highly sensitive fluorescence detection of DNA with dextran coated microarrays

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• 作者：Jie Chao^a ; ¹ ; Zhenhua Li^b ; ¹ ; Jing Li^c ; Hongzhen Peng^b ; Shao Su^a ; Qian Li^b ; Changfeng Zhu^c ; Xiaolei Zuo^b ; Shiping Song^b ; Lianhui Wang^a ; Lihua Wang^b ; ^{wanglihua@sinap.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：DNA detection ; Microarrays ; HCR amplification ; Dextran substrate ; High signal to noise ratio
• 刊名：Biosensors and Bioelectronics
• 出版年：2016
• 出版时间：15 July 2016
• 年：2016
• 卷：81
• 期：Complete
• 页码：92-96
• 全文大小：695 K

文摘

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 (1×10⁵ 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.