Enzymatic synthesis of magnetic nanoparticles.
Int J Mol Sci
; 16(4): 7535-50, 2015 Apr 03.
Article
in En
| MEDLINE
| ID: mdl-25854425
ABSTRACT
We report the first in vitro enzymatic synthesis of paramagnetic and antiferromagnetic nanoparticles toward magnetic ELISA reporting. With our procedure, alkaline phosphatase catalyzes the dephosphorylation of l-ascorbic-2-phosphate, which then serves as a reducing agent for salts of iron, gadolinium, and holmium, forming magnetic precipitates of Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5. The nanoparticles were found to be paramagnetic at 300 K and antiferromagnetic under 25 K. Although weakly magnetic at 300 K, the room-temperature magnetization of the nanoparticles found here is considerably greater than that of analogous chemically-synthesized LnxFeyOz (Ln = Gd, Ho) samples reported previously. At 5 K, the nanoparticles showed a significantly higher saturation magnetization of 45 and 30 emu/g for Fe45±14Gd5±2O50±15 and Fe42±4Ho6±4O52±5, respectively. Our approach of enzymatically synthesizing magnetic labels reduces the cost and avoids diffusional mass-transfer limitations associated with pre-synthesized magnetic reporter particles, while retaining the advantages of magnetic sensing.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ascorbic Acid
/
Alkaline Phosphatase
/
Magnetite Nanoparticles
Language:
En
Journal:
Int J Mol Sci
Year:
2015
Document type:
Article