Conjugated polymer dots emerge as attractive molecular imaging nanoprobes in living animals for their excellent optical properties including bright fluorescence intensity, excellent photostability, high emission rates, and low intrinsic cytotoxicity. This mini-review summarizes recent advances on near-infrared-emitting poly[2-methoxy-5- (2-ethylhexyloxy)-1,4-phenylenevinylene] polymer dots for in vivo bioimaging. The preparation of near-infrared MEH-PPV polymer dots is firstly discussed, followed by some examples of their applications ranging from lymph node mapping and tumor imaging to long-term tumor tracking.

We reported on simple but novel organic light-emitting devices with a thin electron transport layer inserted between a hole-injecting layer and a hole-transporting layer. Unexpectedly, it was observed that charge carriers could easily tunnel through the thin but high barrier and contribute to lower driving voltage and higher electroluminescent efficiency. When fixing the modulation layer for charge carrier tunneling at a thickness of 2.5 nm, we could achieve over 80% improvement in the power efficiency.