Figure 3.

(a) Scheme of sensing mechanism of the glucose oxidase (GOx)-functionalized Au electrode. (b) Exemplary calibration plots of the GOx-functionalized Au electrode in different glucose concentrations for (c) 0.65 V (n = 3) and (d) 0.7 V (n = 3). A linear increasing current response for increasing glucose concentrations was found between 0.025 mM and 2 mM at 0.7 V (inset), whereas the operational range was up to 25 mM at both potentials before saturation occurred. n = number of analyzed samples.