All reagents were at least of analytical grade and used as received without further purification. Double-distilled water was used throughout moreover and a 0.1 M PBS (pH 7.0) served as the supporting electrolyte unless otherwise stated. All electrochemical measurements were performed with a CHI 660A Workstation (CH Instruments, Texas, USA). A conventional three-electrode system, consisting of www.selleckchem.com/products/Lenalidomide.html a working electrode, a Ag/AgCl (saturated KCl) reference electrode and a platinum wire counter electrode, was employed. All the potentials were recorded versus Ag/AgCl. Surface characterization was performed with a JEM-1230 transmission electron microscope (JEOL Instrument, Inc., Japan) at a 100 kV acceleration voltage with a CCD high-resolution camera and a JEM-T300 scanning electron microscope (JEOL Instrument, Inc.
, Japan) with accelerating voltages of 3�C20 kV, respectively.2.2. Fabrication of MWCNTs modified GCEMWCNTs (5 mg) and DHP (5 mg) were dispersed into water Inhibitors,Modulators,Libraries (5 mL) by ultrasonication for about 20 min to give a stable and homogeneous MWCNT-DHP suspension of 1 mg/mL. Prior to Inhibitors,Modulators,Libraries modification, a GCE (3-mm-diameter) was mechanically polished with alumina slurry of different Inhibitors,Modulators,Libraries grades to a mirror finish, rinsed and sonicated in water for 3 min. A MWCNTs modified GCE was prepared Inhibitors,Modulators,Libraries by first dropping MWCNT-DHP suspension (1 mg/mL, 10 ��L) onto the surface of the Inhibitors,Modulators,Libraries GCE and then allowing it to dry under an infrared lamp.2.3. Analytical proceduresA desired volume of Sudan I standard or sample solution was pipetted to a 10 mL electrolytic cell Inhibitors,Modulators,Libraries containing 0.
1 M PBS (pH 7.
0), Inhibitors,Modulators,Libraries followed by deaeration with pumping oxygen-free nitrogen for 10 min. An accumulation step was then conducted with stirring of the solution for 3 min at open-circuit. After a quiescent interval of 30 s, linear sweep voltammograms from �C0.20 to �C1.00 V were recorded. Prior to and after each measurement, Inhibitors,Modulators,Libraries the MWCNTs modified GCE was activated by successive Carfilzomib cyclic voltammetric sweeps from �C0.20 to �C1.00 V at 100 mV/s in the electrolyte solution until the voltammograms Dacomitinib kept unchangeable to achieve a reproducible electrode surface.3.?Results and Discussion3.1.
Surface characterization of the MWCNTs modified selleck catalog GCEA representative transmission electron microscopy (TEM) image demonstrates that the MWCNTs are cylindrical, with outer diameters around 20 nm and with a length ranging from 0.
1 ��m to several www.selleckchem.com/products/17-AAG(Geldanamycin).html micrometers, and each MWCNT is mainly folded in shape (Figure 2a).Figure 2.TEM image of the MWCNTs (a) and SEM image of the MWCNTs modified GCE (b).As shown in the typical scanning electron microscopy (SEM) image of the MWCNTs modified GCE, a uniform film of MWCNTs distributing on the GCE surface is enough stable to resist detachment, and the curved MWCNTs are also observable, forming many defects on the electrode surface (Figure 2b).3.2.