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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Characterization and Interventions for Foodborne Pathogens » Research » Publications at this Location » Publication #322937
Title: Synthesis of amino-rich silica coated magnetic nanoparticles and their application in the capture of DNA for PCR

Author
item BAI, YALONG - Shanghai Jiaotong University
item CUI, YAN - Shanghai Jiaotong University
item Paoli, George
item SHI, CHUNLEI - Shanghai Jiaotong University
item WANG, DAPENG - Shanghai Jiaotong University
item SHI, XIANMING - Shanghai Jiaotong University

Submitted to: Colloids and Surfaces B: Biointerfaces
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/3/2016
Publication Date: 5/4/2016
Citation: Bai, Y., Cui, Y., Paoli, G., Shi, C., Wang, D., Shi, X. 2016. Synthesis of amino-rich silica coated magnetic nanoparticles and their application in the capture of DNA for PCR. Colloids and Surfaces B: Biointerfaces. 145:257-266.

Interpretive Summary: To protect consumer health, food producers and government regulators require rapid, sensitive, and accurate methods to detect harmful bacteria (pathogens) in food. One of the most popular methods for the detection of foodborne pathogens, the polymerase chain reaction (or PCR), is based on the detection of specific DNA sequences associated with the pathogen of interest. Recently, microscopic magnetic particles (nanoparticles) have been used to capture and concentrate DNA prior to PCR, allowing for increased detection sensitivity. This manuscript describes a facile single-pot reaction for synthesis of magnetic nanoparticles that have been chemically modified to increase their efficiency in binding DNA for subsequent PCR-based detection of pathogenic bacteria. The use of these modified nanoparticles will allow for more sensitive PCR-based detection of foodborne pathogens.

Technical Abstract: Magnetic separation has great advantages over traditional bioseparation methods and has become popular in the development of methods for the detection of bacterial pathogens, viruses, and transgenic crops. Functionalization of magnetic nanoparticles is a key factor in allowing efficient capture of the target analytes. In this paper, we report the synthesis of amino-rich silica coated magnetic nanoparticles using a one-pot method. This type of magnetic nanoparticle has a rough network surface and a higher density of amino groups than the nanoparticles prepared by the post-modification method. Furthermore, the results of hydrochloric acid treatment indicated that the magnetic nanoparticles were stably coated. The developed amino-rich silica coated magnetic nanoparticles were used to capture bacterial genomic DNA. After magnetic separation and blocking, the complexes of magnetic nanoparticles and target DNA could be added into a polymerase chain reaction (PCR) directly without onerous and time-consuming steps such as elution and purification. The results of real-time quantitative PCR showed that the nanoparticles with higher amino group density resulted in better separation efficiency. For example, when there was an interferent such as skim milk powder in the DNA solution, the efficiencies of DNA separation using ARSMNPs and nanoparticles prepared by a post-modification method were 60% and 11.5%, respectively. These results suggest that amino-rich silica coated magnetic nanoparticles are of great potential for improved bioseparation of nucleic acids.