The modification of conducting polymer electrodes with antibodies (i.e. proteins) by means of electrochemical polymerization is a simple step that can be used to develop an immunological sensor. However, the electrochemical processes involved leading to the generation of analytical signals by the sensor have not been fully investigated. In this work, we report on the characterization of the interaction between an antigen, human serum albumin (HSA) and an antibody-immobilized polypyrrole electrode (such as anti-HSA) using cyclic voltammetry (CV) and impedance spectroscopy. This interaction was monitored using electrochemical impedance spectroscopy at three different potentials. The potentials correspond to the three redox states of the electroconducting polymer (i.e. reduced, doped and overoxidized states). Evidence from the CV experiments confirmed that there was a shift in the potential, which was found to be proportional to the concentration. Both the CV and the impedance experiments indicated that this potential-dependent shift could be attributed to antibody–antigen (Ab–Ag) binding. 相似文献
We obtain exact lower bounds of the upper limits of ratios of the Nevanlinna characteristics of a delta-subharmonic function in the upper half-plane. 相似文献
In this work, a cooling of a flat microelectronic structure with single-phase forced convection is investigated. The axial
conduction, usually neglected in boundary layer theory, is considered here since the length of the heated element is in the
same order of magnitude as the thickness of the boundary layer. The microstructure represents a package of chips mounted flush
with the surface of the plate, and uniformly heated with a constant heat flux. The differential method is used to reduce the
governing partial differential equations to ordinary differential ones, which are solved numerically by the use of a computational
code developed by the authors. This code is based on Keller–Box method. The temperature profiles and Nusselt numbers are plotted
at several locations on the heated element and are given as functions of the Reynolds number at the beginning of heated microstructure
and of the ratio of unheated to heated length. Furthermore, the average Nusselt numbers on the heated length are computed
for Prandtl numbers in the range 0.7≤Pr≤7,000. The results are compared to the boundary layer solution of unheated starting length problem. The results will be used
as a baseline for successively more complex situations of cooling in electronics. 相似文献
In this paper, we focus on the mathematical and numerical study of a new nonlocal reaction-diffusion system for image denoising. This model is motivated by involving the decomposition approach of $H^{-1}$ norm suggested by Meyer [25] which is more appropriate to represent the oscillatory patterns and small details in the textured image. Based on Schaeffer''s fixed point theorem, we prove the existence and uniqueness of solution of the proposed model. To illustrate the efficiency and effectiveness of our model, we test the denoising experimental results as well we compare with some existing models in the literature. 相似文献
Ohmic contacts to p-type CuCrO2 using Ni/Au/CrB2/Ti/Au contact metallurgy are reported. The samples were annealed in the 200–700 °C range for 60 s in flowing oxygen ambient. A minimum specific contact resistance of 2 × 10−5 Ω cm2 was obtained after annealing at 400 °C. Further increase in the annealing temperature (>400 °C) resulted in the degradation of contact resistance. Auger Electron Spectroscopy (AES) depth profiling showed that out-diffusion of Ti to the surface of the contact stacks was evident by 400 °C, followed by Cr at higher temperature. The CrB2 diffusion barrier decreases the specific contact resistance by almost two orders of magnitude relative to Ni/Au alone. 相似文献
This study presents the preparation of graphene (GR) nanocomposites with polyaniline (PANI) and polypyrrole (PPy) through the fast, versatile and environmentally friendly process of radio frequency (RF)-plasma polymerization. Morphological characterization of the nanocomposites is performed using scanning electron microscopy (SEM) and shows that the PANI and PPy conducting polymers coated the GR surface. The surface properties of the GR nanocomposites are determined using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The prepared GR nanocomposites are then used as counter electrodes in dye-sensitized solar cells (DSSCs). The conversion cell efficiencies for iodine-doped DSSC samples are found to be 0.086%, 5.41%, and 5.60% for I2-PANI, I2-PANI-GR and I2-PPy-GR, respectively, while the corresponding undoped samples reaches power conversion efficiencies of 3.82%, 1.30%, and 0.077% for PPy-GR, PANI-GR and PANI, respectively. The incident photon-to-current efficiency (IPCE) of iodine-doped composite-based DSSCs is significantly enhanced. 相似文献
Several poly(ionic liquids) have been synthesized based on poly(1‐vinyl‐3‐tert‐butoxycarbonylmethylene imidazolium) salts with different counterions to investigate the tert‐butyl ester pyrolysis of these compounds. It is found that the counterions strongly influence the temperature of the pyrolysis. The pyrolysis temperature shifts to higher or lower temperatures depending on the nature of the counterions. The use of microwave irradiation was employed to accelerate the gas release because of the high dipolar interaction of amorphous salts with microwaves. The result of these reactions is the formation of organic foams that could be of industrial interest.