Detection of Single Ion Channel Activity on a Chip Using Tethered Bilayer Membranes

Andersson, Martin; Keizer, Henk M.; Zhu, Chenyu; Fine, Daniel H.; Dodabalapur, A.; Duran, Randolph S.

doi:10.1021/la063503c

Cited by 72 publications

(59 citation statements)

References 14 publications

(29 reference statements)

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“…37,38 Unfortunately, in the present tBLM system, potential-dependent currents did not allow for direct monitoring of the transition between ''open'' and ''closed'' states of an ensemble of hVDAC1 (see ESI, † Fig. S6 and S7).…”

Section: Voltage-induced Structural Changes Of Hvdac1mentioning

confidence: 96%

Voltage-dependent structural changes of the membrane-bound anion channel hVDAC1 probed by SEIRA and electrochemical impedance spectroscopy

Kozuch

Weichbrodt

Millo

et al. 2014

Phys. Chem. Chem. Phys.

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The voltage-dependent anion channel (VDAC) is a transmembrane protein that regulates the transfer of metabolites between the cytosol and the mitochondrium. Opening and partial closing of the channel is known to be driven by the transmembrane potential via a mechanism that is not fully understood. In this work, we employed a spectroelectrochemical approach to probe the voltage-induced molecular structure changes of human VDAC1 (hVDAC1) embedded in a tethered bilayer lipid membrane on a nanostructured Au electrode. The model membrane consisted of a mixed self-assembled monolayer of 6-mercaptohexanol and (cholesterylpolyethylenoxy)thiol, followed by the deposition of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine vesicles including hVDAC1. The stepwise assembly of the model membrane and the incorporation of hVDAC1 were monitored by surface enhanced infrared absorption and electrochemical impedance spectroscopy. Difference spectra allowed for identifying the spectral changes which may be associated with the transition from the open to the ''closed'' states by shifting the potential above or below the transmembrane potential determined to be ca. 0.0 V vs. the open circuit potential. These spectral changes were interpreted on the basis of the orientation-and distancedependent IR enhancement and indicate alterations of the inclination angle of the b-strands as crucial molecular events, reflecting an expansion or contraction of the b-barrel pore. These protein structural changes that do not confirm nor exclude the reorientation of the a-helix are either directly induced by the electric field or a consequence of a potential-dependent repulsion or attraction of the bilayer.

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Section: Voltage-induced Structural Changes Of Hvdac1mentioning

confidence: 96%

Voltage-dependent structural changes of the membrane-bound anion channel hVDAC1 probed by SEIRA and electrochemical impedance spectroscopy

Kozuch

Weichbrodt

Millo

et al. 2014

Phys. Chem. Chem. Phys.

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“…, and/or charged molecules creating electrochemical gradients of cell membranes [285]. Independent of the triggering mechanism, Figure 23 illustrates the simplified structure of an ion channel and the transport of cations through the channel.…”

Section: +mentioning

confidence: 99%

Electrochemical Biosensors - Sensor Principles and Architectures

Grieshaber

MacKenzie

Vörös

et al. 2008

Sensors

819

636

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Quantification of biological or biochemical processes are of utmost importance for medical, biological and biotechnological applications. However, converting the biological information to an easily processed electronic signal is challenging due to the complexity of connecting an electronic device directly to a biological environment. Electrochemical biosensors provide an attractive means to analyze the content of a biological sample due to the direct conversion of a biological event to an electronic signal. Over the past decades several sensing concepts and related devices have been developed. In this review, the most common traditional techniques, such as cyclic voltammetry, chronoamperometry, chronopotentiometry, impedance spectroscopy, and various field-effect transistor based methods are presented along with selected promising novel approaches, such as nanowire or magnetic nanoparticle-based biosensing. Additional measurement techniques, which have been shown useful in combination with electrochemical detection, are also summarized, such as the electrochemical versions of surface plasmon resonance, optical waveguide lightmode spectroscopy, ellipsometry, quartz crystal microbalance, and scanning probe microscopy. The signal transduction and the general performance of electrochemical sensors are often determined by the surface architectures that connect the sensing element to the biological sample at the nanometer scale. The most common surface modification techniques, the various electrochemical transduction mechanisms, and the choice of the recognition receptor molecules all influence the ultimate sensitivity of the sensor. New nanotechnology-based approaches, such as the use of engineered ion-channels in lipid bilayers, the encapsulation of enzymes into vesicles, polymersomes, or polyelectrolyte capsules provide additional possibilities for signal amplification. In particular, this review highlights the importance of the precise control over the delicate interplay between surface nano-architectures, surface functionalization and the chosen sensor transducer principle, as well as the usefulness of complementary characterization tools to interpret and to optimize the sensor response.

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“…15). [179][180][181] A DPTL monolayer was tethered to the gold-coated sensor pads from a DPTL solution in ethanol; then, a lipid monolayer was formed on top of it by vesicle fusion. In view of the very small surface area of the pad, the resistance of the resulting tBLM ranged from 1.5 to 17 G.…”

Section: (A) Gold-supported Thiolipid-based Tblmsmentioning

confidence: 99%