We have previously reported that these pythio-MWNT hybrids could form stable Langmuir-Blodgett (LB) films, which acted as a support to

immobilize hydrogenase (H2ase) [17]. The as-prepared LB films of pythio-MWNTs-H2ase showed strong stability in solutions and higher bioactivity compared with those ordered aggregates formed with polyelectrolytes. Here, the SAMs of pythio-MWNT hybrids were constructed on the gold surface and used as a support to immobilize cytochrome c (Cyt c). The assembly process of SAMs and adsorption of Cyt c were characterized by using quartz crystal microbalance (QCM), Raman spectroscopy, X-ray photoelectron spectroscopy AZD2281 in vivo (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Methods Materials Multiwalled carbon

nanotubes (diameter, 3~10 nm) were purchased from Strem Chemicals (Newburyport, MA, USA). Cytochrome c, 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (DEC), aldrithiol-2, and 2-aminoethylthiol hydrochloride were from Sigma-Aldrich Co. (St. Louis , MO, USA). N N′-dimethylformamide (DMF) was from Fisher Scientific Co. (Hampton, NH, USA). All chemicals were used as received without further purification. S-(2-aminoethylthio)-2-thiopyridine (AETTPy) was synthesized according to the method described by You and coworkers [16] and checked by 1HNMR and elemental analysis [17]. Ultrapure water (18.2 MΩ cm) for the subphases CHIR-99021 solubility dmso was prepared with a Rephile filtration unit (Rephile Bioscience Ltd., Shanghai, China). Functionalization of carbon nanotubes The as-received MWNTs were firstly oxidized using an acid oxidative Methane monooxygenase method [18] and then reacted with AETTPy [16]. The produced pythio-MWNT nanohybrids were collected by centrifugation, washed well with water to remove unreacted reactants, and

finally dried in vacuum. The obtained solid sample of pythio-MWNTs was analyzed by elemental and thermogravimetric analyses as described in our previous work [17]. Self-assembled monolayers Pythio-MWNT nanohybrids were anchored on the surface of AT-cut gold-coated quartz crystals for the QCM and XPS measurements as well as for the morphology characterization. The resonant Dinaciclib cost frequency of the crystals was 9 MHz (5 mm in diameter, Seiko EG&G, Seiko Instruments Inc., Chiba, Japan). The frequency of the QCM was measured with a Seiko EG&G model 917 quartz crystal analyzer. The crystal was mounted in a cell by means of O-ring seals, with only one face in contact with the solution. Before assembly, the crystal was cleaned in a piranha solution (H2SO4/H2O2; 3:1) for 10 min, then washed with a copious amount of water, and finally dried and kept under Ar atmosphere.