## 3 Mechanism of Cyclic Voltammetry Transducer
The peak current can be described mathematically through the following equation:  
\[ip=0.4463\;nFAC\left(\frac{nFvD}{RT}\right)^{1/2} \tag{9}\]  
If the solution @T = 25 \({}^{\circ}\)C, the peak current will be as follows:  
\[ip=\left(2.69\times 10^{5}\right)n^{3/2}AD^{1/2}v^{1/2}C \tag{10}\]  
where,  
\(\mathrm{i_{p}}\) = current maximum in amps  
\(n\) = number of electrons transferred in the redox event  
\(A\) = electrode area in cm\({}^{2}\)  
\(F\) = Faraday Constant in C mol\({}^{-1}\)  
\(D\) = diffusion coefficient in cm\({}^{2}\)/s  
\(C\) = concentration in mol/cm\({}^{3}\)  
\(\
u\) = scan rate in V/s  
\(R\) = Gas constant in J K\({}^{-1}\) mol\({}^{-1}\), \(T\) = temperature in K  
It is clear from the previous equation that the peak current depends on the scan rate, concentration, and diffusion of the electroactive species. The midpoint between the oxidation and reduction peaks is given by:  
\[E_{mid}=\frac{E_{p\;Cathodic}+E_{p\;Anodic}}{2}=E_{0}+\frac{RT}{nF}\ln\left( \frac{D_{r}\frac{1}{2}}{D_{0}\frac{1}{2}}\right)^{2} \tag{11}\]  
where,  
\(E_{0}\) = redox potential  
\(D_{0}\) = Oxidation diffusion coefficient  
\(D_{r}\) = Reduction diffusion coefficient  
The capacitance can be approximately evaluated by the following mathematical expression:  
\[C=\frac{Voltammetric\;Charge}{potential\;window\times Mass} \tag{12}\]  
Hence, the voltammetric charge is defined as the sum of anodic and cathodic charges, then the specific capacitance can be written as:  
\[C=\int\limits_{E_{1}}^{E_{2}}\frac{i\left(E\right)dE}{2(E_{2}-E_{1})mv} \tag{13}\]  
Figure 6: Cyclic voltammetry curves for detailed oxidation and reduction data. (**A**) Scan rate and GOx activity function with potential overtime. (**B**) The cyclic voltammogram. where,  
\(C=\) Specific capacitance  
\(i(E)=\) Instantaneous current  
\((E_{2}-E_{1})=\) potential window width  
\(m=\) mass deposited  
Due to the current equation that addresses the relation between the voltage sweep and the current, the average capacitance can be understood through its mathematical definition:  
\[I=\frac{dQ}{dt}=C\frac{dV}{dt} \tag{14}\]  
\[C=I\frac{dt}{dV} \tag{15}\]  
where,  
\(I=\) faradaic current  
\(\mathrm{d}Q=\) change in charge  
\(\mathrm{d}V/\mathrm{d}t=\) scan rate  
The previous equation demonstrates the relationship between the capacitance, current flow, and scan rate. The fast scan rate generates low capacitance. The overall current and capacitance could be high due to the slow scan rate because the current has the time to flow. The CV analysis is widely used in the non-enzymatic glucose biosensor to measure the electrochemical properties of the electrode towards GOx [81; 94; 95]. [PERSON] et al. [96] successfully fabricated a silver nanowire (Ag NWs)/reduced graphene oxide (rGO) hybrid three-dimensional nanostructure as a working electrode for the ultra-sensitive non-enzymatic glucose sensor. The work is demonstrated at a scan rate of 100 mV/s, while the glucose concentration between 1 to 5 mM was tested in a 0.1 M NaOH solution. The Pt and Ag/AgCl worked as a CE and RE, respectively. While the cyclically applied voltage was between \(-\)0.1 to +0.7 V, the amperometric response was obtained at +0.5 V for the consecutive addition of 1 mM glucose in a 0.1 M NaOH solution. Figure 7 shows a scheme of the CV cell with the electrochemical characterization result. Figure 7: (**A**) The main component of the three-electrode CV cell utilized by Ag NWs/rGO hybrid three-dimensional (3D) electrode as a working electrode, Ag/AgCl as a reference electrode, and Pt electrode as a counter electrode, for glucose detection. (**B**) Results of the sensor with a full description of the oxidation peak and reduction peak at a scan rate of 100 mV/s. Another example demonstrated by [PERSON] et al. [97] synthesized the composition of reduced graphene oxide (rGO)/zinc oxide (ZnO) for non-enzymatic glucose sensors. The group demonstrated the results using the CV technique.