Reagentless Electrochemiluminescence from a Nanoparticulate Polymer of Intrinsic Microporosity (PIM-1) Immobilized onto Tin-Doped Indium Oxide

In contrast to most common electrochemiluminescence (ECL) techniques that require either an additional reagent or continuous pulsing between oxidative and reductive potentials, here a fluorescent polymer of intrinsic microporosity (PIM-1) is shown to exhibit intrinsic ECL without the need for a co-reactant at positive applied potentials and as a function of pH. PIM-1 is known to possess high microporosity (based on its rigid and contorted molecular structure) and excellent fluorescence properties. By depositing a nanoparticulate form of the PIM-1 material onto tin-doped indium oxide, we achieve a hierarchically porous deposit with good sustained ECL activity in aqueous media. The mechanism for this reagentless ECL is suggested to be linked to reactive oxygen species produced at positive potentials and discussed in terms of potential analytical applications.