scholarly journals A label-free aptamer-based nanogap capacitive biosensor with greatly diminished electrode polarization effects

2019 ◽  
Vol 21 (2) ◽  
pp. 681-691 ◽  
Author(s):  
Zahra Ghobaei Namhil ◽  
Cordula Kemp ◽  
Emanuele Verrelli ◽  
Alex Iles ◽  
Nicole Pamme ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Double Layer ◽  
Electrical Double Layer ◽  
Polarization Effect ◽  
Electrode Polarization ◽  
Label Free ◽  
Polarization Effects ◽  
Solution Interface ◽  
Free Ions ◽  
Capacitive Biosensor

A significant impediment to the use of impedance spectroscopy in bio-sensing is the electrode polarization effect that arises from the movement of free ions to the electrode–solution interface, forming an electrical double layer (EDL).

Nanomonitor Technology for Glycosylation Analysis

2009 ◽  
Vol 1236 ◽  
Author(s):  
Gaurav Chatterjee ◽  
Manish Bothara ◽  
Srivatsa Aithal ◽  
Vinay J Nagraj ◽  
Peter Wiktor ◽  
...  
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Printed Circuit Board ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Protein Glycosylation ◽  
Circuit Board ◽  
Biological Macromolecules ◽  
Label Free ◽  
Alumina Membrane

AbstractChanges in protein glycosylation have great potential as markers for the early diagnosis of cancer and other diseases. The current analytical tools for the analysis of glycan structures need expensive instrumentation, advanced expertise, is time consuming and therefore not practical for routine screening of glycan biomarkers from human samples in a clinical setting.We are developing a novel ultrasensitive diagnostic platform called ‘NanoMonitor’ to enable rapid label-free glycosylation analysis. The technology is based on electrochemical impedance spectroscopy where capacitance changes are measured at the electrical double layer interface as a result of interaction of two molecules.The NanoMonitor platform consists of a printed circuit board with array of electrodes forming multiple sensor spots. Each sensor spot is overlaid with a nanoporous alumina membrane that forms a high density of nanowells. Lectins, proteins that bind to and recognize specific glycan structures, are conjugated to the surface of nanowells. When specific glycoproteins from a test sample bind to lectins in the nanowells, it produces a perturbation to the electrical double layer at the solid/liquid interface at the base of each nanowell. This perturbation results in a change in the impedance of the double layer which is dominated by the capacitance changes within the electrical double layer.The nanoscale confinement or crowding of biological macromolecules within the nanowells is likely to enhance signals from the interaction of glycoproteins with the lectins leading to a high sensitivity of detection with the NanoMonitor as compared to other electrochemical techniques.Using a panel of lectins, we were able to detect subtle changes in the glycosylation of fetuin protein as well as differentiate glycoproteins from normal versus cancerous cells. Our results indicate that NanoMonitor can be used as a cost-effective miniature electronic biosensor for the detection of glycan biomarkers.

The Structure of the Electrical Double Layer at the Metal-Solution Interface

1965 ◽  
Vol 65 (6) ◽  
pp. 635-684 ◽  
Author(s):  
M. A. V. Devanathan ◽  
B. V. K. S. R. A. Tilak
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Metal Solution ◽  
Solution Interface

Modeling electrical double-layer effects for microfluidic impedance spectroscopy from 100 kHz to 110 GHz

Lab on a Chip ◽  
2017 ◽  
Vol 17 (15) ◽  
pp. 2674-2681 ◽  
Author(s):  
Charles A. E. Little ◽  
Nathan D. Orloff ◽  
Isaac E. Hanemann ◽  
Christian J. Long ◽  
Victor M. Bright ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Double Layer ◽  
Electrical Double Layer ◽  
Microfluidic Channels ◽  
Frequency Range ◽  
Broad Frequency Range ◽  
On Chip ◽  
Saline Solutions

On-chip microwave calibrations are used to characterize the electrical-double layer response for saline solutions in microfluidic channels over an extremely broad frequency range.

scholarly journals Using nanogap in label-free impedance based electrical biosensors to overcome electrical double layer effect

2015 ◽  
Vol 23 (4) ◽  
pp. 889-897 ◽  
Author(s):  
Ali Kemal Okyay ◽  
Oguz Hanoglu ◽  
Mustafa Yuksel ◽  
Handan Acar ◽  
Selim Sülek ◽  
...  
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Label Free ◽  
Layer Effect ◽  
Electrical Biosensors
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