Ternary Monolayer Interfaces for Ultrasensitive and Direct Bioelectronic Detection of Nucleic Acids in Complex Matrices

Campuzano, Susana; Kuralay, Filiz; Wang, J.

doi:10.1002/elan.201100452

Cited by 20 publications

(18 citation statements)

References 62 publications

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“…Additionally, many biosensors exploit DNA hybridization to detect analytes 12. While interfacial design has been explored in these systems from the perspective of preventing nonspecific adsorption13, 14 or making ssDNA physically accessible to its complementary strand,15, 16 the present work examines the direct influence of interfacial chemistry on DNA hybridization.…”

Section: Introductionmentioning

confidence: 99%

DNA Hairpin Stabilization on a Hydrophobic Surface

Kastantin

Schwartz

2012

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DNA hybridization in the vicinity of surfaces is a fundamental process for self-assembled nanoarrays, nanocrystal superlattices, and biosensors. It is widely recognized that solid surfaces alter molecular forces governing hybridization relative to bulk solution, and these effects can either favor or disfavor the hybridized state depending on the specific sequence and surface. Results presented here provide new insights into the dynamics of DNA hairpin-coil conformational transitions in the vicinity of hydrophilic oligo(ethylene glycol) (OEG) and hydrophobic trimethylsilane (TMS) surfaces. Single-molecule methods are used to observe the forward and reverse hybridization hairpin-coil transition of adsorbed species while simultaneously measuring molecular surface diffusion in order to gain insight into surface interactions with individual DNA bases. At least 35,000 individual molecular trajectories are observed on each type of surface. We find that unfolding slows and the folding rate increases on TMS relative to OEG despite stronger attractions between TMS and unpaired nucleobases. These rate differences lead to nearly complete hairpin formation on hydrophobic TMS and significant unfolding on hydrophilic OEG, resulting in the surprising conclusion that hydrophobic surface coatings are preferable for nanotechnology applications that rely on DNA hybridization near surfaces.

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Section: Introductionmentioning

confidence: 99%

DNA Hairpin Stabilization on a Hydrophobic Surface

Kastantin

Schwartz

2012

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“…A diluent with two thiol groups, HDT, was also evaluated. Due to the higher number of surface‐attaching groups compared with MPA, a lower concentration was needed for ternary monolayer preparation . A concentration range from 1 to 20 μM was examined.…”

Section: Resultsmentioning

confidence: 99%

“…Higher concentrations of DTT, 20 μM and 200 μM, showed higher blanks, lower target signals and very irreproducible results. We attribute this signal decrease observed at high concentrations of DTT to its tendency to remove CP strands from the electrode surface as other authors have described due to the formation of a hydrogen‐bond pseudolayer .…”

Section: Resultsmentioning

confidence: 99%

“…However, recent studies indicate that binary monolayers based on DNA and MCH still display unspecific background contributions due to incomplete backfilling and to the existence of surface defects that may lead to erroneous signals and low reproducibility . In order to solve these problems some authors propose the use of ternary monolayers .…”

Section: Introductionmentioning

confidence: 99%

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Key Factors of Ternary Monolayers to Improve DNA Sensors Performance

et al. 2016

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An important factor affecting the performance of electrochemical genosensors is the immobilization strategy used to anchor the capture probes (CP) on the electrode surface. One of the most common immobilization systems involves the formation of self‐assembled monolayers of thiolated probes on gold surfaces, mainly due to its simplicity and effectiveness. Recent studies have shown that in two‐component thiolated DNA and mercaptohexanol (MCH) monolayers, there is incomplete backfilling that leads to defective surface blockage, producing unspecific background signal. In order to solve these problems, ternary monolayers have been proposed, in which besides MCH as primary diluent, a second diluent is added to enhance the hybridization efficiency and anti‐fouling properties of the surface. Herein, we report a thorough evaluation of different surface chemistries using two different sensors, one for the detection of a peanut allergen encoding sequence and the other one targeting a gluten‐encoding sequence. We assessed the relationship between CP length and the chemical characteristics of the diluents. Factors such as concentration, nature of the functional groups and chain length of the second diluent were evaluated. We found that length of diluents affects primarily the hybridization efficiency, while the type of functional groups, e.g. hydroxyl, carboxyl or a second thiol group, influences the degree of surface coverage. Results diverged between the two sensors evaluated.

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“…Wang's research group was pioneer in the development of ternary DNA SAM‐interfaces prepared by adding, instead of a short monothiol, a short dithiol as co‐adsorbent/backfiller to the common binary SHCP+MCH SAM ,,,,. These ternary SAMs were prepared by co‐immobilization of a short cyclic or linear,, dithiol with the SHCP, followed by chemisorption of MCH in a subsequent step, and provided large signal‐to‐blank ratios.…”

Section: Rational Design Of Surface Chemistrymentioning

confidence: 99%

Tailoring Sensitivity in Electrochemical Nucleic Acid Hybridization Biosensing: Role of Surface Chemistry and Labeling Strategies

2018

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Electrochemical nucleic acid hybridization biosensors have become a mainstay to detect DNA or RNA targets of interest in clinical diagnostics, environmental monitoring and food quality control. Despite the great progress they demonstrated during the last years, there is a constant demand to improve their performance, mainly in terms of sensitivity, simplicity of protocols and easy implementation in routine and decentralized determinations. Within this context, the tremendous possibilities offered by both, a judicious interfacing of the electrode surface, and the use of innovative labeling strategies not requiring nanomaterials or nucleic acid amplification, is discussed critically in this review.

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Ternary Monolayer Interfaces for Ultrasensitive and Direct Bioelectronic Detection of Nucleic Acids in Complex Matrices

Cited by 20 publications

References 62 publications

DNA Hairpin Stabilization on a Hydrophobic Surface

DNA Hairpin Stabilization on a Hydrophobic Surface

Key Factors of Ternary Monolayers to Improve DNA Sensors Performance

Tailoring Sensitivity in Electrochemical Nucleic Acid Hybridization Biosensing: Role of Surface Chemistry and Labeling Strategies

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