Enhancement of biomolecule binding on biosensors using AC electrokinetics

We develop here tools for speeding up binding in a biosensor device through augmenting diffusive transport, applicable to immunoassays as well as DNA hybridization, and to a variety of formats, from microfluidic to microarray. AC electric fields generate the fluid motion through the well documented but unexploited phenomenon, Electrothermal Flow, where the circulating flow redirects or stirs the fluid, providing more binding opportunities between suspended and wall-immobilized molecules. Numerical simulations predict a factor of up to 8 increase in binding rate for an immunoassay under reasonable conditions. Preliminary experiments show qualitatively higher binding after 15 minutes. In certain applications, dielectrophoretic capture of passing molecules, when combined with electrothermal flow, can increase local analyte concentration and further enhance binding.

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DC-biased AC-electrokinetics: a conductivity gradient driven fluid flow

Lab on a Chip ◽

10.1039/c1lc20495e ◽

2011 ◽

Vol 11 (24) ◽

pp. 4241 ◽

Cited By ~ 14

Author(s):

Wee Yang Ng ◽

Antonio Ramos ◽

Yee Cheong Lam ◽

I. Putu Mahendra Wijaya ◽

Isabel Rodriguez

Keyword(s):

Fluid Flow ◽

Ac Electrokinetics ◽

Conductivity Gradient

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An AC electrokinetics-based electrochemical aptasensor for the rapid detection of microRNA-155

Biosensors and Bioelectronics ◽

10.1016/j.bios.2021.113847 ◽

2021 ◽

pp. 113847

Author(s):

Neil Adrian P. Ondevilla ◽

Tak-Wah Wong ◽

Nan-Yao Lee ◽

Hsien-Chang Chang

Keyword(s):

Rapid Detection ◽

Electrochemical Aptasensor ◽

Ac Electrokinetics

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Manipulation of Clinical Materials Using AC Electrokinetics

ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology ◽

10.1115/nemb2010-13367 ◽

2010 ◽

Author(s):

Mandy L. Y. Sin ◽

Pak Kin Wong

Keyword(s):

Experimental Data ◽

Sample Preparation ◽

Theoretical Prediction ◽

Fluid Motion ◽

Lab On A Chip ◽

Clinical Samples ◽

Electrochemical Reactions ◽

Ac Electrokinetics ◽

Wide Range ◽

Electrothermal Flow

AC electrokinetics is a promising approach for sample preparation and reaction enhancement in lab-on-a-chip devices. However, relative little has been done on the electrokinetic manipulation of physiological fluids and buffers with similar properties, such as conductivity. Herein, electrokinetic manipulation of fluids with a wide range of conductivities has been studied as a function of voltage and frequency. AC electrothermal flow is determined to dominate the fluid motion when the applied frequency of the AC potential is above 100 kHz. Interestingly, experimental data deviate from theoretical prediction for fluids with high conductivities (> 1 Sm−1). The deviation can be understood by voltage modulated electrochemical reactions and should be accounted for when manipulating clinical materials with high conductivities. The study will provide useful in sights in designing lab-on-a-chip devices for manipulating clinical samples in the future.

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