Although our GFETs were designed to exhibit a near-zero surface potential and low pH sensitivity through the decoration, the resultant value of ψ0 (or ζ-potential) of the developed GFETs has yet to be evaluated. Therefore, there is potential for further signal enhancement through the optimization of ψ0. The charges of the blocking molecules and capture probes also affected the surface charge of the GFETs. Additionally, the charges of the analyte may also affect the surface charge when the analyte concentration is high. Thus, the design and optimization of the surface charge of GFETs must be tailored to match specific target applications, which will be the focus of future research.