Adsorption of Soft and Hard Proteins onto OTCEs under the Influence of an External Electric Field

Benavidez, Tomás Enrique; Torrente, Daniel; Marucho, Marcelo; Garcı́a, Carlos D.

doi:10.1021/la504890v

Cited by 42 publications

(50 citation statements)

References 50 publications

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“…They investigated the binding/unbinding of the human thrombin and its they observed a decrease in the free energy of binding between the thrombin and aptamer, in presence of positive electric fields. This fact is foreseen also by computations, which showed that the application of positive electric field successfully unbinds the thrombin from the aptamer, confirming the influence of electrostatic potential on the thrombin/aptamer complex, accordingly with the literature [31][32].…”

Section: Aptamers In Electrical Nanobiosensorssupporting

confidence: 78%

Modelling and Development of Electrical Aptasensors, a Short Review

Cataldo¹,

Leuzzi²,

Alfinito³

2018

Preprint

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Selected by in vitro techniques (SELEX, cell-SELEX), aptamers are strands of DNA or RNA molecules able to bind a wide range of targets, from small molecules to live cells, and even tissues, with high affinity and specificity. Due to their efficient targeting ability, aptamers are extensively used in different fields of applications. For example, they ensure high performance as cancer-related markers or in recognizing cancer cells. Actually, they represent a promising way for early diagnosis (biosensors) and to deliver imaging agents and drugs, in both cancer imaging and therapy (therapeutic aptamers). Aptamer-based biosensors (aptasensors) have attracted particular attention over the last decades, so as the possibility of using aptamers in disease therapy in substitution of monoclonal antibodies. The paper briefly reviews the most recent literature on this topic, both concerning the advances in biomedical applications and in the development of electrical aptasensors. The investigation concerning the bioelectronics features of aptamers, to be implemented in the development of electrical nanobiosensors, is also reviewed. To this aim, some recent results of a theoretical/computational framework for modelling the electrical properties of biomolecules (Proteotronics) are reported.

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Section: Aptamers In Electrical Nanobiosensorssupporting

confidence: 78%

Modelling and Development of Electrical Aptasensors, a Short Review

Cataldo¹,

Leuzzi²,

Alfinito³

2018

Preprint

View full text Add to dashboard Cite

show abstract

“…The hydrophobicity map was produced using the hydrophaty index. 14 Recent experimental BSA adsorption studies [15][16][17][18][19][20] have revealed numerous interesting phenomena regarding this protein's behaviour at the surface. However, even modern experimental techniques in isolation have limited access to molecular details such as:…”

Section: Figure1mentioning

confidence: 99%

Bovine Serum Albumin Adsorption at a Silica Surface Explored by Simulation and Experiment

et al. 2017

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Molecular details of BSA adsorption on a silica surface are revealed by fully atomistic molecular dynamics (MD) simulations (with a 0.5 μs trajectory), supported by dynamic light scattering (DLS), zeta potential, multiparametric surface plasmon resonance (MP-SPR), and contact angle experiments. The experimental and theoretical methods complement one another and lead to a wider understanding of the mechanism of BSA adsorption across a range of pH 3-9. The MD results show how the negatively charged BSA at pH7 adsorbs to the negatively charged silica surface, and reveal a unique orientation with preserved secondary and tertiary structure. The experiments then show that the protein forms complete monolayers at ∼ pH6, just above the protein's isoelectric point (pH5.1). The surface contact angle is maximum when it is completely coated with protein, and the hydrophobicity of the surface is understood in terms of the simulated protein conformation. The adsorption behavior at higher pH > 6 is also consistently interpreted using the MD picture; both the contact angle and the adsorbed protein mass density decrease with increasing pH, in line with the increasing magnitude of negative charge on both the protein and the surface. At lower pH < 5 the protein starts to unfold, and the adsorbed mass dramatically decreases. The comprehensive picture that emerges for the formation of oriented protein films with preserved native conformation will help guide efforts to create functional films for new technologies.

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“…It was shown by ellipsometry and MD simulations that soft proteins, such as glucose oxidase, are less sensitive to changes in the conformation under applied potential once immobilized on a solid surface [186]. CueO [187] and fructose dehydrogenase (FDH) [188] adsorbed on a bare gold electrode at potentials around the potential of zero charge (Epzc) showed the highest direct catalytic activity, suggesting a more favorable enzyme orientation.…”

Section: Effect Of Potential Electric Fieldmentioning

confidence: 99%

Controlling Redox Enzyme Orientation at Planar Electrodes

et al. 2018

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Abstract:Redox enzymes, which catalyze reactions involving electron transfers in living organisms, are very promising components of biotechnological devices, and can be envisioned for sensing applications as well as for energy conversion. In this context, one of the most significant challenges is to achieve efficient direct electron transfer by tunneling between enzymes and conductive surfaces. Based on various examples of bioelectrochemical studies described in the recent literature, this review discusses the issue of enzyme immobilization at planar electrode interfaces. The fundamental importance of controlling enzyme orientation, how to obtain such orientation, and how it can be verified experimentally or by modeling are the three main directions explored. Since redox enzymes are sizable proteins with anisotropic properties, achieving their functional immobilization requires a specific and controlled orientation on the electrode surface. All the factors influenced by this orientation are described, ranging from electronic conductivity to efficiency of substrate supply. The specificities of the enzymatic molecule, surface properties, and dipole moment, which in turn influence the orientation, are introduced. Various ways of ensuring functional immobilization through tuning of both the enzyme and the electrode surface are then described. Finally, the review deals with analytical techniques that have enabled characterization and quantification of successful achievement of the desired orientation. The rich contributions of electrochemistry, spectroscopy (especially infrared spectroscopy), modeling, and microscopy are featured, along with their limitations.

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Adsorption of Soft and Hard Proteins onto OTCEs under the Influence of an External Electric Field

Cited by 42 publications

References 50 publications

Modelling and Development of Electrical Aptasensors, a Short Review

Modelling and Development of Electrical Aptasensors, a Short Review

Bovine Serum Albumin Adsorption at a Silica Surface Explored by Simulation and Experiment

Controlling Redox Enzyme Orientation at Planar Electrodes

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