科研之友
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摘要
Chitosan-stabilized Fe3O4 nanoparticles (Fe3O4CHI NPs) are synthesized at room temperature in an aqueous medium and gold NPs are decorated on the surface of these nanoparticles by the deposition/precipitation method. The synthesis of Fe3O4/Au NPs is followed by biofunctionalization with lipoic acid and thereafter the carboxy terminated groups of the Fe3O4/Aulipoic acid composite NPs are coupled to multidentate iminodiacetic acid (IDA) by adopting (1-ethyl-3-(3-dimethylamino propyl) carbodiimide and N-hydroxysulfosuccinimide chemistry. These Fe3O4/AuLAIDA particles are finally allowed to complex with Cu2+ ions resulting in a net positive surface charge. Detailed physicochemical properties of the synthesized NPs have been carried out by XRD, TEM, FT-IR, XPS, TOC, AAS, TG-DTA, and zeta-potential measurements. The super paramagnetic response is investigated by vibrating sample magnetometry and feasibility of these materials as an efficient MRI contrast agent (r2=(124.3+/-13.6) mM-1?s-1) have been also demonstrated in a phosphate-buffered saline suspension. Finally, the Fe3O4/AuLAIDACu2+ composite NPs are used as an immobilized metal affinity matrix to separate expressed His6-tagged protein (>95?% purity) from bacterial lysates and also from a large excess of bovine serum albumin to demonstrate the convenience of using this matrix for rapid purification of heterologously expressed proteins from biological mixtures.
- 出版日期2012-4
