A chemical co-precipitation method capable of controlling the average size and size distribution of magnetic Fe3O4 nano-particles was developed. It was found that the homogeneous variation of the pH value in the solution plays a role in the size distribution of the synthesized Fe 3O4 particles. In this work, we added urea to the ferrite solution, followed by heating the solution to decompose the urea before titrating a base solution into the ferrite solution. Thus, the variation in pH value in the solution can become uniform, and the uniformity in the particles size can be greatly enhanced. In addition, the average particle size is adjustable via control of the amount of urea decomposing at one time. To be biocompatible, dextran is selected as the surfactant for the Fe 3O4 particles, because of its non-toxicity and high bio-affinity. The desired bio-probes can be coated on the dextran layer through adequate chemical reactions.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics