Abstract. The procedures for the synthesis of polypyrrole (PPy) doped with anionic spherical polyelectrolyte brushes (ASPB) (PPy/ASPB nanocomposite) by means of in situ chemical oxidative polymerization were presented. Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopic analysis suggested the bonding structure of PPy/ASPB nanocomposite. Scanning electron microscopy (SEM) was used to confirm the morphologies of samples. The crystallographic structure, chemical nature and thermal stability of conducting polymers were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Thermo-gravimetric analysis (TGA) respectively. Investigation of the electrical conductivity at room temperature showed that the electrical conductivity of PPy/ASPB nanocomposite was 20 S/cm, which was higher than that of PPy (3.6 S/cm).

Abstract. The multistep procedures for preparing novel anionic spherical polyelectrolyte brushes (ASPB) by grafting sodium-p-styrenesulfonate (SSS) from the surface of !-methacryloxypropyl trimethoxy-silane modified SiO 2 nanoparticles were demonstrated. The morphology of ASPB was characterized by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). The core radius R c and hydrodynamic radius R h of ASPB measured by Zeta Potential/Particle Sizer (ZLS) were ca. 50nm and (84.5±1) nm respectively. The percentage of grafting (PG%) of polyelectrolyte brushes was 4.3% investigated by Thermo-gravimetric analysis (TGA). Detailed characterizations on ASPB were performed by cleaving the grafts from the anchoring surface. The molecular weight (M w ) and polydispersity (M w /M n ) of brushes were 1.788·10 3 g/mol and 1.6 respectively from Gel Permeation Chromatography (GPC) measurements. Moreover, R h and !-potential of ASPB in the presence of aqueous NaCl solutions of different concentrations were discussed.

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The goal of this study is to develop a simple one-pot method for the synthesis of a zwitterionic small molecule bearing disulfide moiety, which can effectively inhibit nonspecific protein adsorption on macroscopic and nanoscopic gold surfaces. To this end, the optimal molecular structure of a pyridine disulfide derivative was explored and a zwitterionic small molecule was successfully synthesized from the tertiary amine residue on the pyridine ring through a one-pot method. The coating conditions of the synthesized zwitterionic molecules on the gold surface were optimized through contact angle measurements, and the strong interactions between the gold surface and the disulfide moiety of the zwitterion small molecule were confirmed by surface plasmon resonance (SPR) analysis and X-ray photoelectron spectroscopy. The antibiofouling properties of the coated gold surface were analyzed by fluorescence microscopic observations after contacting with FITC-labeled bovine serum albumin (BSA) and SPR sensor as contacting with BSA solution. In addition, the effect of zwitterion-coating on the salt stability of and protein adsorption on nanoscopic gold surfaces were examined through a NaCl stability test and BSA adsorption test, respectively. From the obtained results, it was confirmed that the simply synthesized zwitterionic small molecule was effective in inhibiting nonspecific protein adsorption on macroscopic and nanoscopic gold surfaces; further, it enhanced the salt stability of gold nanoparticle surfaces.