Microfluidic Arrayed Lab-On-A-Chip for Electrochemical Capacitive Detection of DNA Hybridization Events

Abstract

A microfluidic electrochemical lab-on-a-chip (LOC) device for DNA hybridization detection has been developed. The device comprises a 3 × 3 array of microelectrodes integrated with a dual layer microfluidic valved manipulation system that provides controlled and automated capabilities for high throughput analysis of microliter volume samples. The surface of the microelectrodes is functionalized with single-stranded DNA (ssDNA) probes which enable specific detection of complementary ssDNA targets. These targets are detected by a capacitive technique which measures dielectric variation at the microelectrode-electrolyte interface due to DNA hybridization events. A quantitative analysis of the hybridization events is carried out based on a sensing modeling that includes detailed analysis of energy storage and dissipation components. By calculating these components during hybridization events the device is able to demonstrate specific and dose response sensing characteristics. The developed microfluidic LOC for DNA hybridization detection offers a technology for real-time and label-free assessment of genetic markers outside of laboratory settings, such as at the point-of-care or in-field environmental monitoring.

A review of microfabricated electrochemical biosensors for DNA detection

“…Examples of EIS based sensing using microfabricated sensor systems include the label free DNA sensor based on a DNA modified boron-doped diamond electrode discussed above, through use of alumina nanopore membranes, and an integrated microfluidic system and microelectrode array for detection of DNA hybridization in point of care settings (Weng et al, 2008;Wu et al, 2015;Ben-Yoav et al, 2017). It has been established for gold surfaces that Faradaic and non-Faradaic EIS measurements can yield approximately equal sensitivity and so it is possible to dispense with a redox couple all together.…”

Effect of Electrode Shape and Flow Conditions on the Electrochemical Detection with Band Microelectrodes

“…The use of microelectrodes allows high signal to noise ratio and short electrodic current equilibration times compared to macroelectrodes. Additionally, microelectrodes can be easily implemented in electro-analytical instrumentation where the µL scale must be used, as is the case with lab-on-chip devices [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ].…”