Hydrogen peroxide sensing with nitrogen-doped carbon nanowalls

The fabrication of miniaturized, low-cost, enzyme-free sensors based on nanomaterials via high-performance techniques is expected to provide important benefits for applications in biological detection. In this work, nitrogen-doped carbon nanowalls (CNWs) were synthesized and used to fabricate electrochemical sensor for hydrogen peroxide (H2O2) sensing. The CNWs were grown on Ti\SiO2\Si substrates by radical-injection plasmaenhanced chemical vapor deposition (RI-PECVD) method with different nitrogen concentration. Structural and morphological properties of the obtained CNWs were analyzed using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron microscopy. Cyclic voltammetry and chronoamperometry were used to analyze the electrochemical properties of N-doped CNWs. This study demonstrates the effectiveness of CNWs doping with nitrogen during the synthesis process to improve the electrochemical characteristics of the sensor. It was shown that CNWs doped at high nitrogen flow rate (N2: 20 sccm) exhibited the highest amperometric response. Cyclic voltammetry results indicate that the CNWs doped at high nitrogen flow rate demonstrate excellent electrochemical activity for the reduction of H2O2. These results could pave the way for the development of easy-tomanufacture and highly efficient metal-free biosensors for H2O2 detection.