In situ graphene-modified carbon microelectrode array biosensor for biofilm impedance analysis

Microbial films, formed by the microorganisms to adapt to their living environment, are closely related to the drug resistance and persistent infection of certain diseases such as gingivitis. Impedimetric biosensors could provide an effective means to study the biofilm formation and screening antibiofilm drugs, their performance is closely dependent on the interface materials used thereon. Here, we report a sensitive biosensor platform for this purpose by integration of graphene with carbon microelectrode arrays (C-MEA). A C-MEA was obtained on a silicon substrate through photolithography and subsequent pyrolysis. Characterized by scanning electron microscopy (SEM), Raman spectra, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and electrochemical, we verified that the C-MEAs could evolve into an electrochemically in situ graphene-modified form, GC-MEAs. Using GC-MEA, the growth of biofilm of S. mutans was successfully monitored. Compared to C-MEAs and conventional macrosized counterparts, significant impedance signal amplification and wider detectable frequency range were achieved on the GC-MEAs. Besides, we demonstrated the impedance sensing technology presents high specificity towards the interface-stacked biofilm. The increase in impedimetric signal on the GC-MEAs was 1.4 similar to 2.1 times stronger than that of the C-MEAs and 12.2-13.9 times that of the macrosized electrodes with biofilm growth at a detection frequency of 10.0 kHz. In the last part, the destruction of biofilms grown on the GC-MEAs by using cetylpyridinium chloride was readily monitored by the GC-MEAs senor. In general, graphene-based microelectrode arrays show promise for developing high-throughput drug screening platforms for dealing with detrimental biofilms. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

By integrating graphene with carbon microelectrode arrays, a sensitive biosensor platform has been developed for studying biofilm formation and screening antibiofilm drugs. The graphene-modified microelectrode arrays demonstrated better performance and higher specificity in detecting biofilm growth.