An interesting route using electron-beam lithography and photolithography to pattern submicron interdigitated electrodes array for sensing applications

Increasing the interest in the silicon-based devices resulted in developing new methods and techniques to achieve advanced and more reliable designs and devices. In this study, we have developed a combination method of photolithography and electron-beam lithography (EBL) in order to maximize the efficiency and reducing time and costs. Nanometric and micrometric patterns were created using EBL and photolithography methods, respectively. In order to prove the sensing applications, the EBL-based fabricated electrodes were successfully designed and tested as a hydrogen peroxide (H2O2) biosensor using horseradish peroxidase (HRP) enzyme on a graphene oxide substrate. Photoresist provided a passive layer which reduced the passivation steps in the fabrication. The interdigitated electrodes were used to maximize the connections with the graphene oxide substrate. The result was an ohmic biosensor that exhibits a linear relationship with the logarithm of H2O2 concentration in the range between 0.1 mu M and 100 mM. The limit of detection (LOD) was about 51 nM.