Flexible Microsensor Made of Boron-Doped Graphene Quantum Dots/ZnO Nanorod for Voltammetric Sensing of Hydroquinone

The micro size and mechanical properties of carbon fiber make it an ideal electrode material, but the low surface area of carbon fiber promotes a poor electrochemical response. The combination of graphene quantum dots and metal oxide may modulate their chemical and electrochemical properties, resulting in synergistic signal amplification effect. In this study, a new robust nano-hybrid microelectrode was designed by modifying carbon fiber with boron-doped graphene quantum dots/ZnO nanorod for the electrocatalytic analysis of hydroquinone (HQ). Remarkably, high specific surface area of vertically-aligned ZnO nanorod promoted loading of high-density boron-doped graphene quantum dots. Electrochemical results showed that these modifications promoted a larger active surface area and electron transfer of the carbon fiber microelectrode, as well as enhancement of the electrocatalytic activity toward HQ. Under optimal conditions, the linear response range of the proposed microelectrode to HQ was 0.1 to 100 μ M, and the limit of detection was 0.03 μ M. The proposed microelectrodes show good repeatability, reproducibility and electrode stability. Furthermore, the proposed microelectrode was successfully applied to environmental water samples analysis of HQ, providing a new method for the efficient detection of HQ.