Electrochemistry Research Of Biosensor Based On Nanocomposite Material

In this paper, biosensors based on nanocomposite materials of single-walled carbon nanotubes and cellulose, tetrapeptide-functionalized single-walled carbon nanotubes and platinum nanoparticles modified electrodes was explored. K562 cells were immobilized onto the surface of those carbon nanocomposite modified electrodes by adsorption to form cell sensors. And nano-platinum modified electrode is used as electocatalysis sensor for catalysing methanol, ethanol and hydrogen peroxide directly. Electrochemical methods were used to optimize testing factors and check on their performance. The results show effective electron transfer between the active center of cell and electrode surface. The cells adsorbed onto the modified electrode still kept biological activity and this immobilized method could be used in other biological molecules. And the prepared Pt nanofilm possess good electocatalysis activity own to its special surface.1. The nanocomposite material of cellulose (CL) and single-walled carbon nanotubes (SWNTs), which combined the performance of biocompatibility and conductivity, was expored using the room temperature ionic liquid (RTIL) as intermediary solvent. The electrochemical response of K562 cell immobilized on the nanocomposite material on Au electrode was studied. The selection of RTIL, proportion of CL and SWNTs, influences of scan rate, et al. were discussed. Cyclicvoltammetry (CV) and Electrical Impedance Scanning (EIS) were used to characterize the performance of the cell sensor. Under the optimized experimental conditions, the cell sensor showed a linear range of 1.6×104~1.0×107 cells·mL-1 with a detection limit of 2.6×103 cells·mL-1 according to 3σrule. The sell sensor displayed excellent electrochemical response, high sensitivity, simple preparation. So this study supplied a developed way for the cell sensor and could be used in other area. 2. The K562 cell immobilized on the other carbon nanocomposite material of tetrapeptide (RGDS) functionalized single-walled carbon nanotubes was studied. Following the SWNTs which contained carboxyl groups were activated in N-Hydroxysuccinimide (NHS) and 1-ethyl-3-(3- dimethylaminopropyl) carbodiimide (EDC), RGDS was combined on SWNTs. The conjugated RGDS showed a predominant ability to capture cells on the electrode surface by the specific combination of RGD domains with integrin receptors. Cyclicvoltammetry (CV) was used to characterize the performance of the cell sensor.3. The electrocatalyse electrode of Pt/Au was prepared by electrodeposit platinum nano-bloom on the gilded glass floor. The surface of Pt/Au was characterized by Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS). Cyclicvoltammetry (CV) was used to study its electrocatalysis property of methanol, ethanol and timing current scanning was used to investigate catalysing hydrogen peroxide on nano- platinum. For H2O2, the Pt/Au showed super a stabilization and with a linear range of 0.1-0.9 mM with a detection limit of 0.06 mmol L-1 according to 3σrule.