An Initial Study on Oxidized Graphene-Coated QCM Based Gas Sensor for Cancer Related Volatile Sensing Application

Purpose: The purpose of this preliminary study is to investigate the capability of Graphene Oxide (GO) coated Quartz Crystal Microbalance (QCM) sensor for the detection of cancerous related volatile organic compounds (VOCs). Methodology: The detection of selected six polar and two non-polar VOCs is mainly based on the selectivity and sensitivity of the graphene oxide (GO) films in parts per million (ppm) concentrations. The GO solutions with different concentrations (0.1, 0.5 and 1.0 mg/ml) were coated using the drop coating technique on the both sides of QCM surfaces. These experiments were conducted to study the effect of different GO concentration. An experimental setup was prepared to measure the frequency changes (Δf) of QCM when the sensors were exposed to the synthetic VOCs. In addition, the adsorption characteristic of GO on each odour sample was explained in detail. The surface modifications of QCM with GO film were studied using Field Emission Scanning Electron Microscopy (FESEM). Findings: The results showed that the QCM coated with 1mg/ml was able to respond to minimum concentration of 0.5ppm VOCs. The sensitivity of QCM sensor was observed to be linearly correlated with the (VOCs) concentration given in part per million (ppm). The results demonstrate that the GO coated QCM exhibits high sensitivity and selectivity towards alcohol based vapours. The exposure of each vapour was observed to give different response value. The patterns of the vapour responses were different according to the functional groups. The sensor was also observed to deliver a consistent response under several repetitions. The sensor also exhibited rapid response-recovery performance. Thus, this formulation of GOcoated QCM shows high potential to be a non-invasive cancer screening tool. Originality: This initial study, a low-cost and reproducible GO-QCM based to detect cancerrelated VOCs was investigated. The high sensitivity to polar VOCs and good selectivity information can be referred to classify the cancer types accordingly.