Anodic, cathodic, and annihilation electrochemiluminescence emissions from hydrophilic conjugated polymer dots in aqueous medium.

Hydrophilic poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) conjugated polymer dots (CP-dots) capped by Triton X-100 were synthesized. For the first time, the electrochemiluminescence (ECL) emission of CP-dots was investigated in aqueous solution. At the glassy carbon/water interface, the CP-dots have excellent and multichannel ECL properties, such as having annihilation ECL activity in the absence of coreactants, and give bright anodic and cathodic ECL emission (590 nm) in the presence of tri-n-propylamine (TPrA) and peroxydisulfate (S2O8(2-)), respectively. The versatile ECL properties of the hydrophilic CP-dots combined with their low cytotoxicity, good biocompatibility, and easy bioconjugation may suggest promising applications of this new type of ECL nanomaterial in novel biosensing and bioimaging, and new types of light-emitting devices.