A new star-shaped oligoelectrolyte (TEFCOONa) with triphenylamine as the core, acetylene as linkage and anionic fluorenes as arms was obtained and used for direct imaging in living PANC-1 cells. Because of the hydrophobic conjugated groups of the oli-goelectrolyte, TEFCOONa can form nanospheres with an average diameter of^75 nm in 10 mmol/L PBS. These nanospheres possess a relatively high absolute quantum yield (16.5% in PBS), low cytotoxicity and can penetrate into the nucleus through the cytoplasm, which is essential for living cellular imaging. Collectively, these results validate our rational design of conjugated oligoelectrolyte and even hyper branched polymers-copolyelectrolyte as effective nanovectors for bioimaging and other clinical applications.
SONG WenLiJIANG RongCuiYUAN YanLU XiaoMeiHU WenBoFAN QuLiHUANG Wei
In this paper,we report on the fabrication of a top-emitting electrophosphorescent p-i-n white organic lightemitting diode on the basis of a low-reflectivity Sm/Ag semi-transparent cathode together with a thickness-optimized ZnS out-coupling layer.With a 24-nm out-coupling layer,the reflectivity of the cathode is reduced to 8% at 492 nm and the mean reflectivity is 24% in the visible area.By introducing an efficient electron blocking layer tris（1phenylpyrazolato,N,C2 ＇）iridium（III）（Ir（ppz） 3） to confine the exciton recombination area,the current efficiency and the colour stability of the device are effectively improved.A white emission with the Ir（ppz） 3 layer exhibits a maximum current efficiency of 9.8 cd/A at 8 V,and the Commission Internationale de L＇Eclairage（CIE） chromaticity coordinates are almost constant during a large voltage change of 6 V-11 V.There is almost no viewing angular dependence in the spectrum when the viewing angle is no more than 45,with a CIE x,y coordinate variation of only（±0.0025,±0.0008）.Even at a large viewing angle（75）,the CIE x,y coordinate change is as small as（±0.0087,±0.0013）.
