Web Release Date: January 31,
Magnetic Particle-Based Sandwich Sensor with DNA-Modified Carbon Nanotubes as Recognition Elements for Detection of DNA Hybridization
College of Chemistry and Chemical Engineering, CQKL-LRTA, College of Life Sciences, Southwest University, Chongqing 400715, People's Republic of China
Received for review October 23, 2007. Accepted December 9, 2007.
Abstract:
In this contribution, we design a visual sensor for DNA hybridization with DNA probe-modified magnetic particles (MPs) and multiwalled carbon nanotubes (MWNTs) without involving a visual recognition element such as fluorescent/chemiluminescent reagents. It was found that DNA probe-modified MWNTs, which could be dispersed in aqueous medium and have strong light scattering signals under the excitation of a light beam in the UV-vis region, could connect with DNA probe-modified MPs together in the presence of perfectly complementary target DNA and form a sandwich structure. In a magnetic field, the formed MP-MWNT species can easily be removed from the solution, resulting in a decrease of light scattering signals. Thus, a magnetic particle-based sandwich sensor could be developed to detect DNA hybridization by measuring the light scattering signals with DNA-modified MWNTs as recognition elements. Experiments showed that the DNA-modified MPs sensor could be reused at least 17 times and was stable for more than 6 months.
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