In this study, a novel electrochemical glucose biosensor, which integrates the silicon metal-assisted etching (MAE) technique and the glucose biosensor principle, is proposed. Metal-assisted etching (MAE) method using an AgNO3 and HF mixing solution as the etchant was employed to grow the silicon nanowire array (SNA) electrode. A thin gold shell is then sputtered over each silicon nanowire. Potassium ferricyanide, glucose oxidase (GOx), and a Nafion thin film were then sequentially coated onto the fabricated SNA for glucose detection. The processing time of the MAE and sputtering as well as the GOx concentration were optimized in terms of the redox peak currents of the SNA electrode. Compared with the corresponding plane gold electrode, the effective sensing area of the synthesized SNA electrode was measured to be 6.12 folds. Actual glucose detections illustrated that the SNA based devices could function at a sensitivity of 390.5 μA mM−1 cm−2 with a linear detection range from 55.1 μM–16.53 mM and detection limit of 11 μM. The proposed SNA electrode based glucose biosensor possesses advantages of simple fabrication process, low cost, and high sensitivity. It is feasible for future clinical applications.
Diabetes is a severe public health problem globally. There are about 387 million people worldwide suffer from this medical condition. Regular detection of a diabetes patient’s blood glucose is essential to maintain the blood sugar level. In this study, a novel non-enzyme glucose biosensor based on a simple lithographic process is proposed. Photoresist AZ-1518 is spinning-coated on a silicon wafer. Exposure and development using a mask with hexagonal close-packed circle array is than conducted to generate a hexagonal close-packed column array of the AZ-1518. The diameter of each circle is set as 4 μm. A thermal melting process is than employed to convert each photoresist column into a photoresist hemisphere. Finally, a gold thin film is then sputtered onto the hemisphere array of AZ-1518 to form the sensing electrode. The sensing area is measured to be enhanced by 8.8 folds. Actual glucose detections demonstrated that the proposed simple non-enzyme glucose biosensor can operate in a linear range of 2.8 mM–27.8 mM and a sensitivity of 18.7 μA mM−1cm−2. A detection limit of 9 μM (S/N = 3) was measured. The proposed novel glucose biosensor possesses advantages of enzyme free, simple fabrication process, low cost, and easy to long-term preservation. It is feasible for future clinical applications.
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