Study On The Electrochemical Detection Of The Small Biomolecules Based On Room Temperature Ionic Liquid-based Nanofluids Containing Platinum And Gold Nanoparticles

Nano-fluids was first prepared in1995, which have been used widely in many fields. Water, organic solvent, oil and so on are most popular medium for conventional nano-fluids liquid, but these solvents are with the drawbacks such as terrible thermal stability, easy volatile and bad influence on environment and our health. As a result of those drawbacks, the ionic liquid which has been called’green solvent’have attracted more and more attention by scientists. For the thermal stability and the thermal conductivity of the ionic liquid, the ionic liquid-based nanofluids containing platinum and gold nanoparticles were prepared. The condition of preparation, the size of nano-particles and its stability was discussed.Nano-fluids have high electronic catalyst activity and good electrical conductivit. The ionic liquids have broad electrochemical window and even better electrical conductivity. The ionic liquid-based nanofluids would have a promising future for the application in electrochemical sensor. In this paper, sensors for uric acid, ascorbic acid and dopamine were prepared based on the ionic liquid-based nanofluids containing metal nanoparticles. These developments have make a great difference in electrochemistry.The main contents and results of this paper are described as follows:1>[BMIm] BF4ionic liquid used as liquid medium, polyvinyl pyrrolidone (PVP) as a stabilizer and extractant, ionic liquid-based nanofluids containing platinum (ILPtNFs) was synthesized with the assistant of ultrasonic. The prepared nano-fluids was chartered with1H-NMR spectrum, transmission electron microscopy and fourier transform infrared spectroscopy. The results showed that the prepared nano-fluids has uniform size, good distribution and stability. There is chemical bond interaction between PVP and platinum nanoparticles. Due to the surface modification effect on the nanoparticles, the prepared nano-fluids was uniformed and stabled. The ionic liquid-based nanofluids containing gold nanoparticles (ILAuNFs) was prepared with the same method. 2、With ILPtNFs as the modified material, an electrochemical sensor for detecting dopamine (DA) was prepared by immobilizing the ILPtNFs on a glassy carbon electrode surface with nafion-ethanol. The cyclic valtammetric method was adopted to research the electrochemical behavior of DA on the modified electrode. A new detected method of DA was developed by differential pulse valtammetry (DPV). In phosphate buffer solution (pH=7.0), ILPtNFs had obvious electro-catalysis effect on DA. A pair of well-defined quasi-reversible redox peaks of DA was obtained on the modified electrode. Under the experimental optimized condition, the DA oxidation peak current demonstrated the good linear relationship with the concentration of DA in the range of4.0×l0-6-1.0×10-4mol/L. The detection limit was1.32×10-7mol/L. This method can be applied to determine the content in the actual sample of DA hydrochloride injection with satisfactory results.3、The electrochemical sensor is prepared by fixed ILAuNFs on the glassy carbon electrode by drop-coating. The behavior of uric acid (UA) and DA on the modified electrode have been texted with cyclic voltammetry and established a new method for the determination of UA and DA with differential pulse voltammetry (DPV). Our experimental results show that LAuNFs has obvious electro-catalytic activity for UA and DA. DA presented a reversible redox peaks on the modified electrode, and DA and UA are separated well. Under the optimized experimental conditions, UA and DA peak showed good linear relationship with its concentration in the range from4.0×10-6to1.0×10-4mol/L and the detection limits are1.32×10-7mol/L and1.8×10-7mol/L respectively. This method can be used for the quantitative detection of UA and DA in samples.