“…These third generation biosensors are composed of electrodes (e.g., glassy carbon electrode, porous gold electrode, etc.) and are functionalized with composite materials such as sensing elements (e.g., carbon nanotubes [CNTs]) and immobilized GOx (du Toit & Di Lorenzo, ; M. Zhang et al, ; Sağlam, Kızılkaya, Uysal, & Dilgin, ; Shrestha et al, ; Suganthi, Arockiadoss, & Uma, ; Tian, Alex, Siegel, & Tiwari, ; X. P. Zhang, Liu, Li, & You, ; Xu, Sheng, Shen, & Zheng, ; Y. Yu et al, ). The presence of endogenous electroactive metabolites and impurities, the long distance between redox cofactor and electrode surface, and the orientation of GOx on the electrode, though, are difficult challenges for the development of direct electron transfer approaches (Bartlett & Al‐Lolage, ; Luong, Glennon, Gedanken, & Vashist, ).…”