In this work, the laser-scribing technique was used as a low-cost, rapid and facile method for fabricating digital microfluidic (DMF) systems. Laser-scribed graphene (LSG) electrodes are directly synthesized on flexible substrates to pattern the DMF electrode arrays. This facilitates the DMF electrodes’ fabrication process by eliminating many microfabrication steps. An electrowetting test was performed to investigate the effectiveness of the LSG DMF electrodes in changing the contact angles of droplets. Different DMF operations were successfully performed using the proposed LSG DMF chips in both open and closed DMF systems. The quality and output resolution were examined to assess the performance of such patterned electrodes in the DMF systems. To verify the efficacy of the LSG DMF chips, a one-step direct assay for the detection of Legionellapneumophila deoxyribonucleic acid (DNA) was performed on the chip without the need for any washing step. The high specificity in distinguishing a single-nucleotide mismatch was achieved by detecting target DNA concentrations as low as 1 nM. Our findings suggest that the proposed rapid and easy fabrication method for LSG DMF electrodes offers a great platform for low-cost and easily accessible point-of-care diagnostic devices.

中文翻译：

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低成本的基于石墨烯的数字微流体系统

在这项工作中，激光划刻技术被用作制造数字微流控（DMF）系统的低成本，快速且简便的方法。激光划刻石墨烯（LSG）电极直接在柔性基板上合成，以对DMF电极阵列进行构图。通过消除许多微制造步骤，这有助于DMF电极的制造过程。进行了电润湿测试，以研究LSG DMF电极在改变液滴接触角方面的有效性。使用建议的LSG DMF芯片，在开放式和封闭式DMF系统中都成功执行了不同的DMF操作。检查了质量和输出分辨率，以评估DMF系统中此类图案化电极的性能。为了验证LSG DMF芯片的功效，可通过一步法直接检测在芯片上进行了嗜肺军团菌脱氧核糖核酸（DNA）检测，而无需任何清洗步骤。通过检测低至1 nM的目标DNA浓度，可以实现区分单核苷酸错配的高特异性。我们的发现表明，建议的用于LSG DMF电极的快速简便的制造方法为低成本和易于访问的即时诊断设备提供了一个很好的平台。