A novel immobilization strategy for electrochemical detection of cancer biomarkers: DNA-directed immobilization of aptamer sensors for sensitive detection of prostate specific antigens

Yang, Z. , Kasprzyk-Hordern, B., Goggins, S., Frost, C. G. and Estrela, P. (2015) A novel immobilization strategy for electrochemical detection of cancer biomarkers: DNA-directed immobilization of aptamer sensors for sensitive detection of prostate specific antigens. Analyst, 140(8), pp. 2628-2633. (doi: 10.1039/C4AN02277G) (PMID:25756086)

Abstract

We report on a novel strategy for DNA aptamer immobilization to develop sensitive electrochemical detection of a protein biomarker, with prostate specific antigen (PSA) as a case biomarker. Thiolated single-stranded DNA (ssDNA) was co-immobilized with 3-mercapto-1-propanol on gold electrodes, and used as a scaffold for DNA aptamer attachment through hybridization of the aptamer overhang (so-called “DNA-directed immobilization aptamer sensors”, DDIAS). In the approach, the complementary DNA aptamer against PSA was assembled by the probe ssDNA onto the electrode to detect PSA; or the probe ssDNA directly hybridized with a complementary DNA aptamer/PSA complex following their pre-incubation in solution, so-called ‘on-chip’ and ‘in-solution’ methods, respectively. A double stranded DNA intercalator with a ferrocenyl (Fc) redox marker was synthesized to evaluate the feasibility of the strategy. The results demonstrate that the ‘in-solution’ method offers a favourable medium (in a homogeneous solution) for the binding between the aptamer and PSA, which shows to be more efficient than the ‘on-chip’ approach. DDIAS shows promising analytical performance under optimized conditions, with a limit of detection in the range of fM and low non-specific adsorption.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Yang, Dr Zhugen
• Authors: Yang, Z., Kasprzyk-Hordern, B., Goggins, S., Frost, C. G., and Estrela, P.
• College/School: College of Science and Engineering > School of Engineering > Biomedical Engineering
• Journal Name: Analyst
• Publisher: Royal Society of Chemistry
• ISSN: 0003-2654
• ISSN (Online): 1364-5528