Leakage-Free Nucleic Acid Biochip Featuring Bioinert Photocurable Inhibitor

Norshah Rizal Ali,Motasem H Ghanim,Mohamad Adzhar Md Zawawi,Mohd Zaid Abdullah

doi:10.1109/access.2021.3113382

Norshah Rizal Ali, Motasem H Ghanim + Show 2 more

Open Access

https://doi.org/10.1109/access.2021.3113382

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Abstract

A leakage-free and disposable biochip for deoxyribonucleic acid (DNA) separation and detection is developed in this study. The biochip comprises of 50 mm long polydimethylsiloxane (PDMS) microchannel and copper electrodes engraved on flame retardant (FR-4) printed circuit board (PCB) substrate. An inhibitor made from photocurable diacrylate bisphenol-A polymer (DABA) was used to establish a permanent bonding between PDMS and PCB substrates. Pull-off test experiments resulted in average strength of 287.4 kPa and a standard deviation of ± 23.8 kPa. These results are comparable to recent studies on leak-free microfluidic applications. Meanwhile, the leakage test showed that the biochip could withstand a pressure of more than 190 kPa, which is sufficiently high for most DNA measurements. Finally, experiments performed on two different DNA samples indicated that the proposed design could accurately detect DNA fragments with current sensitivity higher than 100 nA, under electric field strength of 20 V/cm. The new design effectively seals the biochip, thus preventing leakage of liquid from the sensor matrix. Together with its biologically and electrochemically inert characteristic, it opens up possibilities in building a truly portable biosensing device.

Highlights

Recent outbreaks of respiratory infections in humans, including MERS-CoV, SARS-CoV-1, and SARS-CoV-2 (COVID-19) viruses, emphasize the importance of rapid process, point-of-care technology (POCT) diagnostic tools that can be deployed in the community
We developed a novel technique for permanently attaching printed circuit board (PCB) to PDMS to VOLUME XX, 2017 address this issue, thereby preventing microfluidic spillage from the sensor
Each unit is composed of a working electrode (WE), a reference electrode (RE), and a counter electrode (CE)

Summary

Introduction

Recent outbreaks of respiratory infections in humans, including MERS-CoV, SARS-CoV-1, and SARS-CoV-2 (COVID-19) viruses, emphasize the importance of rapid process, point-of-care technology (POCT) diagnostic tools that can be deployed in the community. The circuit-board and polymer-based microfluidic devices are the emerging diagnostic tools that offer portable, easy miniaturization, biocompatible and cost-effective materials [1,2,3]. Another significant advantage of the construction is the range of materials that can be utilized to build a leak-free diagnostic tool [1]. Bonding can be classified either directly or indirectly, where indirect bonding involves the assistance of an intermediate material like an adhesive. Indirect bonding employed multiple strategies to avoid channel clogging by sealing the two incompatible surfaces with an intermediate substance

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