Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/46572

TitleElectrochemical aptasensor for human osteopontin detection using a DNA aptamer selected by SELEX
Author(s)Meirinho, S.
Dias, Luís G.
Peres, António M.
Rodrigues, L. R.
KeywordsOsteopontin
SELEX
DNA aptamers
Screen-printed gold electrode
Electrochemical aptasensor
Issue date22-Sep-2017
PublisherElsevier
JournalAnalytica Chimica Acta
CitationMeirinho, S.; Dias, Luís G.; Peres, António M.; Rodrigues, Lígia R., Electrochemical aptasensor for human osteopontin detection using a DNA aptamer selected by SELEX. Analytica Chimica Acta, 987, 25-37, 2017
Abstract(s)A DNA aptamer with affinity and specificity for human osteopontin (OPN), a potential breast cancer biomarker, was selected using the SELEX process, considering its homology rate and the stability of its secondary structures. This aptamer exhibited a satisfactory affinity towards OPN, showing dissociation constants lower than 2.5 nM. It was further used to develop a simple, label-free electrochemical aptasensor against OPN. The aptasensor showed good sensitivity towards OPN in standard solutions, being the square wave voltammetry (SWV), compared to the cyclic voltammetry, the most sensitive technique with detection and quantification limits of 1.4 ± 0.4 nM and 4.2 ± 1.1 nM, respectively. It showed good reproducibility and acceptable selectivity, exhibiting low signal interferences from other proteins, as thrombin, with 2.610 times lower current signals-off than for OPN. The aptasensor also successfully detected OPN in spiked synthetic human plasma. Using SWV, detection and quantification limits (1.3 ± 0.1 and 3.9 ± 0.4 nM) within the OPN plasma levels reported for patients with breast cancer (0.44.5 nM) or with metastatic or recurrent breast cancer (0.98.4 nM) were found. Moreover, preliminary assays, using a sample of human plasma, showed that the aptasensor and the standard ELISA method quantified similar OPN levels (2.2 ± 0.7 and 1.7 ± 0.1 nM, respectively). Thus, our aptasensor coupled with SWV represents a promising alternative for the detection of relevant breast cancer biomarkers.
TypeArticle
URIhttp://hdl.handle.net/1822/46572
DOI10.1016/j.aca.2017.07.071
ISSN0003-2670
e-ISSN1873-4324
Publisher versionhttp://www.elsevier.com/locate/issn/00032670
Peer-Reviewedyes
AccessOpen access
Appears in Collections:CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series

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