Electrokinetically Controlled DNA Hybridization Microfluidic Chip Enabling Rapid Target Analysis

Abstract

Biosensors and more specifically biochips exploit the interactions between a target analyte and an immobilized biological recognition element to produce a measurable signal. Systems based on surface nucleic acid hybridization, such as microarrays, are particularly attractive due to the high degree of selectivity in the binding interactions. One of the drawbacks of this reaction is the relatively long time required for complete hybridization to occur, which is often the result of diffusion-limited reaction kinetics. In this work, an electrokinetically controlled DNA hybridization microfluidic chip will be introduced. The electrokinetic delivery technique provides the ability to dispense controlled samples of nanoliter volumes directly to the hybridization array (thereby increasing the reaction rate) and rapidly remove nonspecific adsorption, enabling the hybridization, washing, and scanning procedures to be conducted simultaneously. The result is that all processes from sample dispensing to hybridization detection can be completed in as little as 5 min. The chip also demonstrates an efficient hybridization scheme in which the probe saturation level is reached very rapidly as the targets are transported over the immobilized probe site enabling quantitative analysis of the sample concentration. Detection levels as low as 50 pM have been recorded using an epifluorescence microscope.

Review on Impedance Detection of Cellular Responses in Micro/Nano Environment

“…Due to their miniaturization and automation, there are a number of advantages of using microfluidic systems, such as less sample/reagent consumption, reduced risk of contamination, less cost per analysis, lower power consumption, enhanced sensitivity and specificity, and higher reliability. Microfluidic systems have been developed for various biological analytical applications, such as DNA analysis [4][5][6][7][8], immunoassay [9][10][11][12][13], and cell analysis [14][15][16][17][18]. Moreover, a number of demonstrations showed that cell culture can be performed on the microfluidic systems to achieve higher throughput and more reliable results [19,20].…”

Microfluidic DNA hybridization assays

“…Another limitation of the surfacebased DNA hybridization assays is the relative long time for hybridization reaction, typically requires several hours or more because it generally depends solely on the diffusion of target DNA to the surface-bound probes (Jobs et al 2002). However, Erickson et al (2004) introduced an electrokinetically controlled DNA hybridization microfluidic chip based on surface DNA hybridization. They utilized electroosmotic driven flow in their system to deliver samples/reagents, which increased the reaction rate.…”

“…With the rapid growth of the microfluidic technology, microarrays and microfluidic biochips have been extensively employed as promising tools for DNA analysis over the past decade (Berti et al 2009;Cao et al 2010;Chen et al 2008;Heule and Manz 2004;Javanmard and Davis 2011;Mai et al 2007;Mulvaney et al 2007;Jin et al 2009;Kwakye and Baeumner 2003;Li and He 2009;Senapati et al 2009). The advantages of applying microfluidics platform in DNA hybridization have been demonstrated in many representative works (Fan et al 1999;Erickson et al 2004;Ali et al 2003;Sun and Kwok 2006;Ferguson et al 2009). It has been demonstrated that the ability to do DNA analysis with micrometre resolution facilitates the realization of a functional hybridization assay (Lange et al 2004).…”

Microfluidic Systems for Diagnostic Applications: A Review

“…These devices were integrated into a single chip and worked cooperatively to perform a specific assay. Various biological analytical applications, such as DNA analysis, [24][25][26] immunoassay, [27][28][29][30] and cell analysis, [31][32][33][34] have been demonstrated using microfluidic systems. For example, a microfluidic-based DNA analysis system integrated with microchannels, heaters, temperature sensors, and fluorescence detectors was capable of capturing the DNA, mixing the solutions together, amplifying the DNA, and separating and detecting those products.…”