Fast assembly of non-thiolated DNA on gold surface at lower pH

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:411

Article

Jiang, Hui¹  Materon, Elsa M.^2,3,4  Taboada Sotomayor, Maria Del Pilar⁴  Liu, Juewen^2,3 

[1] Southeast Univ, State Key Lab Bioelect, Nanjing 210096, Jiangsu, Peoples R China

[2] Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada

[3] Univ Waterloo, Waterloo Inst Nanotechnol, Waterloo, ON N2L 3G1, Canada

[4] State Univ Sao Paulo, Inst Chem, Dept Analyt Chem, UNESP, BR-14801970 Araraquara, SP, Brazil

关键词: DNA;    Adsorption;    Gold;    Biosensors;    Immobilization;   

DOI  :  10.1016/j.jcis.2013.08.043

来源: Elsevier

【 摘 要 】

In a typical protocol for attaching DNA to a gold electrode, thiolated DNA is incubated with the electrode at neutral pH overnight. Here we report fast adsorption of non-thiolated DNA oligomers on gold electrodes at acidic pH (i.e., pH similar to 3.0). The peak-to-peak potential difference and the redox peak currents in typical cyclic voltammetry of [Fe(CN)(6)](3-) are investigated to monitor the attachment. Compared with incubation at neutral pH, the lower pH can significantly promote the adsorption processes, enabling efficient adsorption even in 30 min. The adsorption rate is DNA concentration-dependent, while the ionic strength shows no influence. Moreover, the adsorption is base-discriminative, with a preferred order of A > C >> G, T, which is attributed to the protonation of A and C at low pH and their higher binding affinity to gold surface. The immobilized DNA is functional and can hybridize with its complementary DNA but not a random DNA. This work is promising to provide a useful time-saving strategy for DNA assembly on gold electrodes, allowing fast fabrication of DNA-based biosensors and devices. (C) 2013 Elsevier Inc. All rights reserved.

【 授权许可】

Free