uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Structural Changes of Mercaptohexanol Self-assembled Monolayers on Gold and their Influence on Impedimetric Aptamer Sensors
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.ORCID iD: 0000-0002-1769-4382
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.ORCID iD: 0000-0003-3843-7198
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.ORCID iD: 0000-0003-4395-7905
Show others and affiliations
2019 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 91, no 22, p. 14697-14704Article in journal (Refereed) Published
Abstract [en]

Despite a large number of publications describing biosensors based on electrochemical impedance spectroscopy (EIS), little attention has been paid to the stability and reproducibility issues of the sensor interfaces. In this work, the stability and reproducibility of faradaic EIS analyses on the aptamer/mercaptohexanol (MCH) self-assembled monolayer (SAM) functionalized gold surfaces in ferri- and ferrocyanide solution were systematically evaluated prior to and after the aptamer-probe DNA hybridization. It is shown that the EIS data exhibited significant drift, and this significantly affected the reproducibility of the EIS signal of the hybridization. As a result, no significant difference between the charge transfer resistance (RCT) changes induced by the aptamer-target DNA hybridization and that caused by the drift could be identified. A conditioning of the electrode in the measurement solution for more than 12 hours was required to reach a stable RCT baseline prior to the aptamer-probe DNA hybridization. The monitored drift in RCT and CDL during the conditioning suggests that the MCH SAM on the gold surface reorganized to a thinner but more closely packed layer. We also observed that the hot binding buffer used in the following aptamer-probe DNA hybridization process could induce additional MCH and aptamer reorganization thus further drift in RCT. As a result, the RCT change caused by the aptamer-probe DNA hybridization was less than that caused by the hot binding buffer (blank control experiment). Therefore, it is suggested that the use of high temperature in the EIS measurement should be carefully evaluated or avoided. This work provides practical guidelines for the EIS measurements. Moreover, since SAM functionalized gold electrodes are widely used in biosensors, e.g., DNA sensors, an improved understanding of the origin of the observed drift is very important for the development of well-functioning and reproducible biosensors.

Place, publisher, year, edition, pages
2019. Vol. 91, no 22, p. 14697-14704
National Category
Analytical Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-397690DOI: 10.1021/acs.analchem.9b03946ISI: 000498280100072PubMedID: 31650834OAI: oai:DiVA.org:uu-397690DiVA, id: diva2:1372336
Funder
Swedish Foundation for Strategic Research , ICA 12-0047Swedish Foundation for Strategic Research , FFL15-0174Swedish Research Council, VR 2014-5588Knut and Alice Wallenberg Foundation, Wallenberg Academy Fellow ProgramAvailable from: 2019-11-22 Created: 2019-11-22 Last updated: 2020-01-13Bibliographically approved
In thesis
1. Interface Studies for Gold-based Electrochemical DNA Sensors
Open this publication in new window or tab >>Interface Studies for Gold-based Electrochemical DNA Sensors
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Gold based label-free electrochemical DNA sensors have been widely studied for biomarker diagnostics. The sensitivity and reproducibility of these sensors are determined by the sensing interface: the DNA modified gold surfaces. This thesis systematically studies the preparation processes of the DNA sensor interfaces as well as their effects on the sensor performance. First, three pretreatment methods to clean the gold electrode surface and their influence on the subsequent binding of thiolated molecules were carefully investigated. As we found that the surface pretreatment method involving cyclic voltammetry (CV) in H2SO4 may induce structural changes to the gold surface, thus greatly impacting the thiolated molecule binding, the factors influencing this pretreatment method were studied. Practical guidelines were summarized for preparing a clean and reproducible gold surface prior to functionalization. Afterwards, the effects of the surface coverage density of probe DNA and the salt concentration on the probe-target DNA hybridization on a gold sensing surface were systematically investigated using surface plasmon resonance (SPR) analysis. Based on the SPR results, the maximum potentiometric signal that could be generated by the DNA hybridization on the surface, and the detection limits, were estimated for different experimental conditions. These estimations were further compared with experimental results obtained using silicon nanowire field effect transistors (SiNW FET) with DNA modified gold on the gate oxide. Practical limitations for the potentiometric DNA sensor were analysed and discussed. Finally, the stability and reproducibility issues on the electrochemical impedance spectroscopy (EIS) analyses of DNA hybridization were also studied on the aptamer/mercaptohexanol (MCH)-modified gold surface. The root cause for the drift problems in this type of sensor and the temperature effects on the aptamer/MCH modified surface were identified. This thesis could serve as a practical reference for the preparation and understanding of the sensing interface of gold-based electrochemical DNA sensors.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2019. p. 83
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1882
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:uu:diva-397807 (URN)978-91-513-0824-1 (ISBN)
Public defence
2020-01-20, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2019-12-18 Created: 2019-11-25 Last updated: 2020-01-14

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textPubMed

Authority records BETA

Xu, XingxingMakaraviciute, AstaWen, ChenyuSjödin, MartinAbdurakhmanov, EldarDanielson, U. HelenaNyholm, LeifZhang, Zhen

Search in DiVA

By author/editor
Xu, XingxingMakaraviciute, AstaWen, ChenyuSjödin, MartinAbdurakhmanov, EldarDanielson, U. HelenaNyholm, LeifZhang, Zhen
By organisation
Solid State ElectronicsNanotechnology and Functional MaterialsBiochemistryScience for Life Laboratory, SciLifeLabInorganic Chemistry
In the same journal
Analytical Chemistry
Analytical Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 15 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf