کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
867277 | 909780 | 2012 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A microfluidic-based electrochemical biochip for label-free diffusion-restricted DNA hybridization analysis A microfluidic-based electrochemical biochip for label-free diffusion-restricted DNA hybridization analysis](/preview/png/867277.png)
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.
► We fabricate a microfluidic lab-on-a-chip device.
► The device contains an array of individually addressable 25 nL reaction chambers.
► We detect DNA hybridization with electrochemical impedance spectroscopy analysis.
► Restricted diffusion model is used for the first time to analyze DNA hybridization.
► We detect ssDNA targets selectively and with a calculated detection limit of 3.8 nM.
Journal: Biosensors and Bioelectronics - Volume 38, Issue 1, October–December 2012, Pages 114–120