Department of Materials Engineering, Ming Chi University of Technology, New Taipei City, 243303, Taiwan.
Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital, Taoyuan, 33378, Taiwan.
Mikrochim Acta. 2022 Sep 7;189(10):374. doi: 10.1007/s00604-022-05463-7.
A chemiresistive biosensor is described for simple and selective detection of miRNA-21. We developed chemical vapor deposition (CVD) and low-damage plasma treatment (LDPT)-treated bilayer graphene composite of graphene oxide/graphene (GO/GR) for the determination of a reliable biomarker. We have successfully overcome the self-limiting growth mechanism by using CVD method to grow more than one layer of graphene on copper foil. In addition, LDPT can be used to form GO/GR structures for chemiresistive biosensor applications. Due to the direct formation of BLGR (bilayer graphene), the coupling between graphene layers is theoretically superior to that of stacked BLGR, which is also confirmed by the blue shift of the characteristic peak of graphene in Raman spectroscopy. The shift is about double compared with that of stacked BLGR. Based on the results, the limit of detection for the target miRNA-21 was calculated to be 5.20 fM and detection rage is calculated as 100 fM to 10 nM, which is obviously better performance. Compared with previous work, this chemiresistive biosensor has good selectivity, and stability towards detection of miRNA-21. The ability to detect miRNA-21 in different biological fluids was almost identical to that in pH 7.4 phosphate-buffered saline (PBS). Thus, the proposed bilayer GO/GR of modified chemiresistive biosensor may potentially be applied to detect cancer cells in clinical examinations.
本文描述了一种用于简单、选择性检测 miRNA-21 的化学电阻式生物传感器。我们开发了化学气相沉积（CVD）和低损伤等离子体处理（LDPT）处理的氧化石墨烯/石墨烯（GO/GR）双层石墨烯复合材料，用于确定可靠的生物标志物。我们已经成功地克服了自限制生长机制，使用 CVD 方法在铜箔上生长了超过一层的石墨烯。此外，LDPT 可用于形成 GO/GR 结构，用于化学电阻式生物传感器应用。由于 BLGR（双层石墨烯）的直接形成，石墨烯层之间的耦合在理论上优于堆叠 BLGR，这也通过拉曼光谱中石墨烯特征峰的蓝移得到了证实。与堆叠 BLGR 相比，这种蓝移大约是其两倍。基于这些结果，计算出目标 miRNA-21 的检测限为 5.20 fM，检测范围为 100 fM 至 10 nM，性能明显更好。与之前的工作相比，这种化学电阻式生物传感器具有良好的选择性和稳定性，可用于检测 miRNA-21。在不同生物流体中检测 miRNA-21 的能力与在 pH 7.4 磷酸盐缓冲盐水（PBS）中几乎相同。因此，所提出的改性化学电阻式生物传感器的双层 GO/GR 可能有潜力应用于临床检查中的癌细胞检测。
