Fabrication of Noncoplanar Molecule Aggregates with Inherent Porous Structures for Electrochemiluminescence Signal Amplification.

A simple and time-saving strategy was developed for the amplification of electrochemiluminescence (ECL) by dropping the noncoplanar tetraphenylethylene (TPE) solution on the surface of gold electrode. The self-assembled TPE aggregates exhibited inherent porous structures, endowing them with high specific surface area and oxygen adsorption capability. Therefore, the fabricated porous structures could lead to a 50-fold increase in the ECL signal of luminol in neutral aqueous solution, in comparison to that on the bare electrode. In contrast, the aggregates of the two typical coplanar polycyclic aromatic hydrocarbons (PAHs), perylene and pyrene, gave a weaker ECL enhancement, owing to their disc-like molecular structure and densely packed layers under aggregated conditions. The proposed ECL system has been successfully applied for the detection of hydrogen peroxide (H2O2) in the linear range of 0.25-1000 μM with a detection limit (S/N = 3) of 0.1 μM. Our findings provide inspiration for revealing the role of inherent molecular structure in the aggregate configuration, and they provide attractive perspectives for the usage of noncoplanar molecules in analytical applications.