|Title||A microfluidic-based electrochemical biochip for label-free diffusion-restricted DNA hybridization analysis.|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Ben-Yoav, H, Dykstra, PH, Bentley, WE, Ghodssi, R|
|Date Published||2012 Oct-Dec|
|Keywords||Biosensing Techniques, Diffusion, DNA, Single-Stranded, Electrochemical Techniques, Limit of Detection, Microfluidic Analytical Techniques, Oligonucleotide Array Sequence Analysis|
DNA hybridization detection in microfluidic devices can reduce sample volumes, processing times, and can be integrated with other measurements. However, as device footprints decrease and their complexity increase, the signal-to-noise ratio in these systems also decreases and the sensitivity is thereby compromised. Device miniaturization produces distinct properties and phenomena with greater influence at the micro-scale than at the macro-scale. Here, a diffusion-restriction model was applied to a miniaturized biochip nanovolume reactor to accurately characterize DNA hybridization events that contribute to shifts in both charge transfer resistance and diffusional resistance. These effects are shown to play a significant role in electrochemical impedance spectroscopy (EIS) analyses at these length scales. Our highly functional microfluidic biosensor enables the detection of ssDNA targets selectively, with a calculated detection limit of 3.8 nM, and cross-reactivity of 13% following 20 min incubation with the target. This new biosensing approach can be further modeled and tested elucidating diffusion behavior in miniaturized devices and improving the performance of biosensors.
|Alternate Journal||Biosens Bioelectron|