Synthesis and Characterization of Enzyme Nanoparticles.
EMSL Project ID
9797
Abstract
The detection of protein is of central importance to the diagnosis and treatment of human diseases, for the detection of infectious agents, and for reliable forensic analysis. The emergence of nanotechnology is opening new horizons for the application of nanoparticles in analytical chemistry. In particular, nanomaterials are of considerable interest in the world of nanoscience owing to their unique physical and chemical properties. Such properties offer excellent prospects for chemical and biological sensing. Particularly attractive for numerous bioanalytical applications are colloidal gold and semiconductor quantum dot nanoparticles. The power and scope of such nanoparticles can be greatly enhanced by coupling them with biological recognition reactions and electrical processes (i.e. nanobioelectronics). Such coupling can dramatically enhance biological assays.Since the sensitivity of such electrical bioassays using nanoparticle tags depends on the size of particle tag, a dramatic amplification of the hybridization signals is expected in connection to micrometer-size tracers (instead of nanometric ones). We have developed a series of metal nanoparticles for electrochemical DNA hybridization assay, for example: Quantum dots (ZnS, PbS, CdS) [1, 2], core-shell Fe@Au nanoparticles[3]. In order to amplify the detection sensitivity, we also designed an amplification platform to load multiple metal nanoparticles and enzyme [4,5]. The detection limit has moved to Zepta mole and the developed amplification platform can be used to detect 825 copies in 25 l sample. In order to move the detection limit to single molecular level, we plan to prepare big size materials (micrometer length ) or Enzyme nanoparticle (100~200 nm) as tags for electric DNA and protein detection as well as protein direct electrochemistry and biosensor application.
Because of catalytic amplification properties, enzyme is often used as tag for the electrochemical, optical bioassay. Dual enzyme cycling amplification and loading enzyme molecules to carriers (nanotube, spheres) were used to increase the detection sensitivity, which reached to ftomole or zpmole. The presented methods are based on single molecular tracer (The diameter of a single enzyme molecular ranges from 1 nm to 10 nm), which limited the further enhancement of sensitivity. In my protocol, I will prepare some enzyme nanoparticles (HRP, ALP, GOX) by dissolvent method. The size of prepared enzyme nanoparticles is about from 100 nm to 500 nm. The characterise and dessolvation process will be optimized. The particle size, zeta potential, and the number of available amino groups on the surface of the nanoparticles will be determined. To facilitate the application of prepared enzyme nanoparticles, the Enzyme nanoparticles will be modified with avidin or thiol group. The prepared particles will have wide applications on electric DNA detection, protein direct electrochemistry and biosensor.
Application:
1. Enzyme nanoparticle as tag for Electric DNA detection
2. Enzyme nanoparticle for protein direct electrochemistry and Biosensors
Project Details
Project type
Exploratory Research
Start Date
2004-08-26
End Date
2007-07-06
Status
Closed
Released Data Link
Team
Principal Investigator