Highly sensitive non-enzymatic electrochemical glucose biosensor using a photolithography fabricated micro/nano hybrid structured electrode

•We report a highly sensitive non-enzymatic glucose biosensor based on a simple photolithographic process.•A uniform micro/nano hybrid structured electrode of gold was fabricated.•The sensing area was measured to be enhanced by 10.2 folds.•The linear range, sensitivity, and limit of detection were measured to be 55.6 μM–13.89 mM, 749.2 μA mM−1 cm−2, and 9 μM, respectively.

In this study, a novel non-enzymatic glucose biosensor based on a simple photolithographic process is proposed. To fabricate the sensor, photoresist AZ-1518 was spin-coated onto a reclaimed silicon wafer, and then, a mask with a hexagonal close-packed circle array was employed for exposure and development to generate a hexagonal close-packed column array of AZ-1518. The diameter of each circle was set as 3 μm. Subsequently, a thermal melting process was employed to convert each photoresist column into a photoresist hemisphere. A gold thin film was then sputtered onto the hemisphere array of AZ-1518 to form the sensing electrode. Finally, gold nanoparticles were deposited onto the gold thin film using a self-assembly monolayer method to enhance the sensing area. Measurements showed a 10.2-fold enhancement of the sensing area in comparison with a plain gold electrode. Actual detection of glucose demonstrated that the proposed non-enzymatic glucose biosensor can operate in a linear range of 55.6 μM–13.89 mM. It had a sensitivity of 749.2 μA mM−1 cm−2 and a detection limit of 9 μM. The novel glucose biosensor proposed here has several advantages such as being enzyme free, simple to fabricate, low cost, and easy to preserve on a long-term basis. Thus, it can feasibly be used for future clinical applications.