Song Jin, Li Yiwei, Yin Fang, Zhang Zhitao, Ke Dingkun, Wang Dianbing, Yuan Qipeng, Zhang Xian-En
Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, North Third Ring Road 15, Chaoyang District, Beijing 100029, China.
National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
ACS Sens. 2020 Jun 26;5(6):1795-1803. doi: 10.1021/acssensors.0c00570. Epub 2020 May 21.
Biofilms can cause many bacterial diseases, such as dental disease. An detection of biofilms may help to screen antibiofilm drugs. An impedance measurement based on an Au electrode has been successfully used for real-time monitoring of animal and human cell growth. However, microbial growth on the Au electrode produced a poor signal because of the small size of microbial cells. We have recently demonstrated that graphene derivatives can be produced on a carbon electrode through facile electrochemical activation, thus forming a reduced graphene oxide-carbon electrode (rGO-CE). Based on this fact, we hypothesized that an formed rugose graphene layer of rGO-CE may provide a large surface area for the growth of microbial biofilms and can therefore produce a strong impedance signal in response to a change in the biomass. In this study, three oral bacteria, (), (), and (), were cultured on the surfaces of rGO-CE. As a result, the impedance response signal of the rGO-CE for the growth of and was found to be 3.3 times and 6.0 times stronger than that of the Au electrode at 1.17 and 54.7 kHz, respectively. In particular, the poorly adhering strain of also produced a detectable signal on the graphene electrode but not on the Au electrode at 1.17 kHz. Furthermore, destructions of the biofilms grown on the rGO-CE by cetylpyridinium chloride were successfully monitored by impedance changes. Overall, it is promising to develop a graphene-based impedance biosensor platform for biofilm study and antibiofilm drug screening.
生物膜可引发多种细菌性疾病，如牙科疾病。生物膜的检测有助于筛选抗生物膜药物。基于金电极的阻抗测量已成功用于实时监测动物和人类细胞的生长。然而，由于微生物细胞尺寸小，金电极上的微生物生长产生的信号较弱。我们最近证明，可通过简便的电化学活化在碳电极上制备石墨烯衍生物，从而形成还原氧化石墨烯 - 碳电极（rGO - CE）。基于这一事实，我们推测rGO - CE形成的粗糙石墨烯层可为微生物生物膜的生长提供大表面积，因此可响应生物量变化产生强烈的阻抗信号。在本研究中，三种口腔细菌，即变形链球菌（Streptococcus mutans）、牙龈卟啉单胞菌（Porphyromonas gingivalis）和具核梭杆菌（Fusobacterium nucleatum），在rGO - CE表面进行培养。结果发现，在1.17 kHz和54.7 kHz时，rGO - CE对变形链球菌和牙龈卟啉单胞菌生长的阻抗响应信号分别比金电极强3.3倍和6.0倍。特别是，在1.17 kHz时，粘附性差的具核梭杆菌菌株在石墨烯电极上也产生了可检测信号，但在金电极上未产生。此外，通过阻抗变化成功监测了十六烷基吡啶氯化物对rGO - CE上生长的生物膜的破坏。总体而言，开发基于石墨烯的阻抗生物传感器平台用于生物膜研究和抗生物膜药物筛选具有广阔前景。
