Non-enzymatic glucose biofuel cell (GBFC) have attracted wide attention due to the rapid development of wearable or implantable medical devices. This can be credited to the fact that they can generate electricity directly from the oxidation of biological organic matter. Generally, biofuel cells can be divided into two categories according to the type of catalyst used: microbial biofuel cells and enzymatic biofuel cells. Glucose is recognized as the most essential energy source for many living organisms and even biofuel cells owing to its natural abundance, renewability, non-toxicity, and ease of production. As such, GBFCs have attracted wide attention due to the rapid development of wearable or implantable medical devices. However, enzyme-based GBFCs demand the use of a noble metal catalyst to overcome several shortfalls: for instance, the potential for poisoning, limited enzyme stability and cumbersome enzyme immobilization procedures. Research has revealed that the introduction of a catalyst helps bypass these drawbacks. To date, the most popular catalyst has been platinum metal. Unfortunately, in addition to their prohibitive cost, Pt based anodes are susceptible to interferences and tend to generate an oxide layer that often compromises their power output by consequently reducing their efficiency.

Energy conversion in a GBFC highly depends on the effective catalytic area of the electrode. Therefore, for actual applications, characteristics such as high energy conversion efficiency, low cost, long-term stability, ease of production, and high reproducibility are required. In this view, researchers from the National Chung-Hsing University: Dr. Tien-Fu Chu, Dr. Raja Rajendran and Professor led by Gou-Jen Wang, in collaboration with Dr. Iren Kuznetsova at the Russian Academy of Science developed a high-power, non-enzymatic glucose biofuel cell based on a nano/micro hybrid-structured Au anode. Their work is currently published in the  Journal of Power Sources.

In their approach, a uniformly distributed micro-hemispheric array of polycarbonate was fabricated for this novel electrode by hot embossing using a Ni mold. The nano/micro hybrid-structured Au anode was then fabricated by depositing an Au nanoparticle monolayer on the micro-hemispheric array using 1,6-hexanedithiol as a two-sided anchor. The cathode was composed of a graphene film-coated glassy carbon electrode. The researchers used Nafion, a proton exchange membrane, to separate the anode and cathode and complete the battery assembly.

Results of their experiments revealed that the proposed non-enzymatic GBFC had a high-power density of 10.7 mWcm ^-2, a high current density of 29.5 mAcm ^-2, an open-circuit voltage of 8.2 V, and a shorted-circuit current of 34 mA at room temperature. In addition, the energy conversion efficiency of the electrode was calculated to be 52.47%.

In summary, the study reported on the development of a high-power, non-enzymatic GBFC based on a nano/micro hybrid-structured Au anode. The unique feature of their anode was a monolayer of Au nanoparticles uniformly deposited on the electrode surface; hence, the glucose oxidation ability of the anode was significantly enhanced. Overall, the proposed GBFC can easily be produced on a large scale, is of relatively low cost, has high repeatability, and can be preserved for long periods of time without great losses in performance. As such, the study by Gou-Jen Wang and colleagues presented a GBFC highly feasible for commercialization and use in practical applications.