Graphene quantum dots functionalized three-dimensional ordered mesoporous ZnO for acetone detection toward diagnosis of diabetes
The development of high-performance semiconductor oxide sensor for accuracy detection of trace disease biomarkers in exhaled breath is still a challenge that urgently needs to be addressed. Here, we propose a self-assemble strategy and spin-coating process to create graphene quantum dots (GQDs) functionalized three dimensional order macroporous (3DOM) ZnO structure. The strong synergistic effect and the p−n heterojunction between p-type GQDs and n-type ZnO effectively enlarged the resistance variation due to the change in oxygen adsorption. The specific 3DOM structure induced hierarchical pore size (286 nm in macroscale and 26 nm in mesoscale) and 3D interconnection which guarantee the high gas accessibility and fast carrier transportation. As a result, GQDs modified 3DOM ZnO sensor exhibits remarkably high response (Rair/Rgas = 15.2 for 1 ppm acetone), rapid response/recovery time (9/16 s), extremely low theoretical detection limit (10 ppb), and good selectivity towards acetone against other interfering gases. In particular, proposed sensor can accurately distinguish the trace acetone in simulation diabetes exhaled breath test. These results demonstrate a high potential for the feasibility of GQDs modified 3DOM SMO structure as new sensing material for the possibility of noninvasive real-time diagnosis of diabetes.