Effect of Boron-Doping Level and Surface Termination in Diamond on Electrogenerated Chemiluminescence

Electrogenerated chemiluminescence (ECL) is a phenomenon of light emission from a molecular species that is triggered by an electrochemical reaction. As with many electrochemical systems, ECL is highly dependent on the electrode material and its surface state. Boron-doped diamond (BDD) has been applied for ECL, however, thoughtful investigation remains scarce. In particular, a peculiar feature of BDD is the tuning of its properties by changing the amount of boron doping which in turn affects the electrochemical response. Here, we summarize the results from the most important ECL systems, such as Ru(bpy)32+ (bpy = 2,2′-bipyridine)/tri-n-propylamine (TPrA), Ru(bpy)32+/S2O82–, Ru(bpy)32+/SO42–, Ru(bpy)32+/CO32–, and the luminol/CO32– system, by using BDD and correlating the doping level to the ECL response. We showed that the most suitable boron doping level and surface state are highly dependent on the ECL system investigated, highlighting the importance of the right choice of the BDD electrode. While focused on ECL systems, these results offer a general interpretation and might be adapted to different electrochemical systems where BDD finds application.