Addition of Lithium 8‑Quinolate into Polyethylenimine Electron-Injection Layer in OLEDs: Not Only Reducing Driving Voltage but Also Improving Device Lifetime

Solution-processed electron injection layers (EILs) comprising lithium 8-quinolate (Liq) and polyethyl­enimine ethoxylated (PEIE) are highly effective for enhancing electron injection from ZnO to organic layers and improving device lifetime in organic light-emitting devices (OLEDs). Doping of Liq into PEIE further reduces the work function of zinc oxide (ZnO) by enhancing dipole formation. The intermolecular interaction between Liq and PEIE was elucidated by UV–vis absorption measurement and quantum chemical calculation. The OLEDs with ZnO covered with PEIE:Liq mixture exhibited lower driving voltage than that of the device without Liq. Furthermore, as doping concentration of Liq into PEIE increased, the device lifetime and voltage stability during constant current operation was successively improved

Generation of Novel Anti-MUC1 Monoclonal Antibodies with Designed Carbohydrate Specificities Using MUC1 Glycopeptide Library

Numerous anti-mucin 1 (anti-MUC1) antibodies that recognize <i>O</i>-glycan core structures have already been developed. However, most of them show low specificities toward <i>O</i>-glycan structures and/or low affinity toward a monovalent epitope. In this study, using an MUC1 glycopeptide library, we established two novel anti-MUC1 monoclonal antibodies (1B2 and 12D10) with designed carbohydrate specificities. Compared with previously reported anti-MUC1 antibodies, 1B2 and 12D10 showed quite different features regarding their specificities, affinities, and reactivity profiles to various cell lines. Both antibodies recognized specific <i>O</i>-glycan structures at the PDT*R motif (the asterisk represents an <i>O</i>-glycosylation site). 1B2 recognized <i>O</i>-glycans with an unsubstituted <i>O</i>-6 position of the GalNAc residue (Tn, T, and 23ST), whereas 12D10 recognized Neu5Ac at the same position (STn, 26ST, and dST). Neither of them bound to glycopeptides with core 2 <i>O</i>-glycans that have GlcNAc at the <i>O</i>-6 position of the GalNAc residue. Furthermore, 1B2 and 12D10 showed a strong binding to not only native MUC1 but also 20-mer glycopeptide with a monovalent epitope. These anti-MUC1 antibodies should thus become powerful tools for biological studies on MUC1 <i>O</i>-glycan structures. Furthermore, the strategy of using glycopeptide libraries should enable the development of novel antibodies with predesigned <i>O</i>-glycan specificities

Conjugated Polyelectrolyte Blend with Polyethyleneimine Ethoxylated for Thickness-Insensitive Electron Injection Layers in Organic Light-Emitting Devices

Electron injection layers (EILs) based on a simple polymer blend of polyethyleneimine ethoxylated (PEIE) and poly­[(9,9-bis­(3′-((<i>N</i>,<i>N</i>-dimethyl)-<i>N</i>-ethylammonium)-propyl)-2,7-fluorene)-<i>alt</i>-2,7-(9,9-dioctylfluorene)] (PFN-Br) can suppress the dependence of organic light-emitting device (OLED) performance on thickness variation compared with single PEIE or PFN-Br EILs. PEIE and PFN-Br were compatible with each other and PFN-Br uniformly mixed in the PEIE matrix. PFN-Br in PEIE formed more fluorene–fluorene pairs than PFN-Br alone. In addition, PEIE:PFN-Br blends reduced the work function (WF) substantially compared with single PEIE or PFN-Br polymer. PEIE:PFN-Br blends were applied to EILs in fluorescent polymer-based OLEDs. Optimized PEIE:PFN-Br blend EIL-based devices presented lower driving voltages and smaller dependences of device performance on EIL thickness than single PEIE or PFN-Br-based devices. These improvements were attributed to electron-transporting fluorene moieties, increased fluorene–fluorene pairs working as channels of electron transport, and the large WF reduction effect of PEIE:PFN-Br blends