Engineering Defects in Graphene Oxide for Selective Ammonia and Enzyme-Free Glucose Sensing and Excellent Catalytic Performance for para-Nitrophenol Reduction.

Recently, extensive attention has been given to developing an active and durable metal-free economical sensor and catalyst. Graphene oxide (GO)-based sensors and catalysts have been considered as a promising candidate in current material science research. However, the sensing and catalytic properties of GO also need to be further improved to satisfy the specific applications, such as gas detection in harsh environments, medical diagnosis based on human breath, blood glucose detection, catalytic activity, and so forth. Therefore, the effect of nitrogen in GO on the performance of glucose and ammonia sensing, and catalytic activity has been investigated. Herein, we propose a practical, high-sensitive sensor and catalyst based on high-quality defect N-enriched GO. One-step, low-cost solvothermal synthesis of N-enriched GO has been exploited for the development of high-performance sensors and excellent catalyst at room temperature. The resultant N-enriched GO (N8GO) has been studied as a promising sensing material for ammonia, glucose, and para-nitrophenol (PNP) reduction. The prevalent outstanding sensing and catalytic performance may be due to the synergistic effect of nitrogen. A probable mechanism for sensing and catalytic reduction of PNP using N8GO has been proposed.