文摘
In this contribution, we design a visual sensor for DNAhybridization 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 thatDNA probe-modified MWNTs, which could be dispersedin aqueous medium and have strong light scatteringsignals under the excitation of a light beam in the UV-vis region, could connect with DNA probe-modified MPstogether in the presence of perfectly complementary targetDNA and form a sandwich structure. In a magnetic field,the formed MP-MWNT species can easily be removedfrom the solution, resulting in a decrease of light scattering signals. Thus, a magnetic particle-based sandwichsensor could be developed to detect DNA hybridizationby measuring the light scattering signals with DNA-modified MWNTs as recognition elements. Experimentsshowed that the DNA-modified MPs sensor could bereused at least 17 times and was stable for more than 6months.