## 6 Conclusions  
The CV detection technique is a way for electrochemical characterization of the electrode's performance towards a very specific molecule. The non-enzymatic glucose sensor normally uses this technology for analysis purposes of the glucose. Graphene-based nanocomposites are widely used in non-enzymatic glucose sensors because of their unique properties, sensitivity, cost-effective, and green purpose. Despite the scientific effort, the graphene-based electrode for the portable non-enzymatic glucose sensor has not been developed yet. While a few numbers of articles in this field focus on the preparation of new electrodes based on graphene that could be applicable for electrochemical reactions, the understanding limitation of the material reaction with the glucose directly affects the large-scale production. The understanding of the reaction between the graphene nanocomposites and glucose would give a chance to develop rapidly. To do so, the ISO standard should be followed. There are basic components that need to be tested during the experiments; selectivity (must select the target only), sensitivity for the target, no oxygen-dependent, stability, accuracy, precision, low cost, biocompatibility, and easy fabrication. However, graphene and its nanocomposites still promise many chances for future non-enzymatic glucose sensor development. The unique electrochemical properties of graphene-based non-enzymatic glucose sensors make the scalability the first concern for a high scale production with successful commercialization. Despite many ways that have been demonstrated for graphene fabrication, there are not enough methods that could produce graphene at a low-cost demand. Hence, the CVD method is promising for cost-effectiveness, high scale production, which could be used directly for the fabrication of non-enzymatic glucose sensor systems at low cost. The electrocatalytic activities of the graphene-based non-enzymatic glucose sensor depend on the graphene structure (purity), still, there is a lack of information and understanding for these details, which means there are many things that should be detailed for this issue. Although the low experimental efforts were investigated for low-contact resistance between the catalyst and current collector, the high resistance was still maintained as a barrier for the highly efficient non-enzymatic glucose sensors. The limitation of the study for most research efforts on graphene sheets makes the possibility of rapid progress low. There is a huge chance of making high-performance non-enzymatic glucose sensors if the research is considered for nanoparticles, dots, ribbons, etc. The rapid progress in graphene-based non-enzymatic glucose sensors will lead to the fourth generation of sensors that could be implemented for bio-information sensors and microfluidic chips. Somehow, this could help the patient.  
W.C., formal analysis, writing--review and editing, visualization, supervision, and funding acquisition; M.H.F.T., the formal author, conceptualization, formal investigation, writing--review and editing, and project administration; H.A., a second author, formal writing and editing. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The author has submitted some parts of this work as a part of the Postgraduate Certificate of Nanotechnology at the department of continuing education, the University of Oxford, UK. The work was titled \"Cyclic voltammetry transducer for biosensors.\" The Article Processing Charge (APC) of this paper is funded by Wahyu Caesarendra.  
The authors declare no conflict of interest.