| Protein microarrays have been exhibited the advantages such as miniaturization and high throughput, which can be used for multiplex and parallel assay of biochemistry and molecular biology in proteome research. Traditional cloning-expressing-purification-spotting is still the basic standard procedure for the fabrication of protein microarrays. However, these procedures are tedious, time and labor intensity with high cost of production, which have been the main bottle neck in the development and application of protein microarrays. To bypass the traditional procedure, we describe a simple and low-cost protein microarray strategy, wherein the microarrays are generated by printing linear DNA molecules on a microarray surface that can be converted into protein microarrays through cell-free synthesis system. The linear DNA molecules are immobilized onto the slide by biotin-avidin interaction along with biotin-labeled anti-GST antibody. Each protein of interest is synthesized as GST-fusion protein. Thus the in situ cell-free synthesized proteins can be recognized by its capture antibody arrayed on the slide. This antigen-antibody binding can immobilize the protein on the surface in a microarray format. The proteins yielded by this approach are ranged from 0.35 fmol to 4.0 fmol per spot. We also investigate the detection methods for protein microarray, and the detection limit increases 100 folds with tyramide signal amplification (TSA) compared to the traditional fluorescent detection.Ionic liquids (ILs) can be used either as supporting electrolyte or modifier for electrode in the field of electroanalysis. Since electroanalysis has inherent advantages such as lower detection limit and wider dynamic range, it can be used to investigate the electrochemical behaviors of biomolecules. In this thesis two kinds of ionic liquid modified electrodes were fabricated:The first kind of ionic liquid modified carbon paste electrode (CILE) was constructed based on the substitute of paraffin with 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]BF4) to mix with graphite powder. Then methylene blue (MB) was electropolymerized on the CILE by using the cyclic voltammetric technique in the potential range from -1.0 V to 0.8 V (vs. SCE). The stable polymer film was obtained and exhibited a pair of redox peaks. The morphology and characteristics of poly (methylene blue) (PMB) film was studied by the techniques such as scanning electron microscopy and electrochemical impedance spectroscopy. This PMB modified CILE (PMB/CILE) showed excellent electrocatalytic response to 3, 4-dihydroxybenzoic acid with the increase of the electrochemical responses. The oxidation peak current had a linear relationship with 3,4-dihydroxybenzoic acid concentration in the range of 5.0×10-4 ~ 3.0×10-2 mol/L and the detection limit was got as 1.72×10-4 mol/L (3σ).The second ionic liquid modified electrode was constructed based on Nafion and hydrophobic ionic liquid of 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) composite film modified carbon paste electrode (CPE). The direct electrochemistry of Mb in the Nafion-BMIMPF6/CPE was achieved with a pair of well-defined redox peaks appeared. The results indicated that Nafion-BMIMPF6 composite film provided a suitable microenvironment to realize the direct electron transfer between Mb and CPE. The cathodic and anodic peak potentials were located at -0.351 V and -0.263 V (vs. SCE) with the apparent formal peak potential (Ep) as -0.307 V, which was the characteristic of Mb Fe(III)/Fe(II) redox couples. Mb modified electrode showed excellent electrocatalytic activity towards trichloroacetic acid (TCA) with the linear concentration range from 2.0×10-4 mol/L to 1.1×10-2 mol/L and the detection limit as 1.6×10-5 mol/L (3σ).
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