Fluorescent Detection of Specific DNA Sequences Related to Toxoplasma gondii Based on Magnetic Fluorescent Nanoparticles Fe3O4/CdTe Biosensor
Lei He
Department of Applied Chemistry, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, 300387, Tianjin, China
Liusong Ni
Department of Applied Chemistry, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, 300387, Tianjin, China
Xueping Zhang
Department of Applied Chemistry, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, 300387, Tianjin, China
Chen Zhang
Department of Applied Chemistry, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, 300387, Tianjin, China
Shichao Xu *
Department of Materials Science, State Key Laboratory of Hollow Fiber Membrane Materials and Membrane Process, Tianjin Polytechnic University, 300387, Tianjin, China
*Author to whom correspondence should be addressed.
Abstract
Fluorescent Detection of Specific DNA Sequences Related to Toxoplasma gondii Based on Magnetic Fluorescent Nanoparticles Fe3O4/CdTe Biosensor
Magnetic fluorescent nanoparticles (Fe3O4/CdTe) were prepared in this work and applied for Toxoplasma gondii DNA detection. First, CdTe quantum dots were synthesized with 3-mercaptopropionic (MPA) capped. Fe3O4 magnetic particles were prepared by hydrothermal method with NaOH as precipitator, and they were surfacely modified with silane coupling agent (KH550). After then, the MPA-capped CdTe QDs were immobilized on the Fe3O4 particles surface via electrostatic interaction, and the Fe3O4/CdTe particles were prepared with the average size of 10 nm. The DNA sensing probe was fabricated through labeling a stem-loop Toxoplasma gondii DNA oligonucleotides with Fe3O4/CdTe (donor) at the 5′ end and BHQ2 (acceptor) at 3′ end, respectively. The assembly prosess was verified by UV-Vis, TEM, IR, XRD etc. The sensitivity characterization of the molecular beacon probe was performed by fluorescence spectrum (FS) with a detection limit of 8.339x10-9M. This chemical strategy can be further applied to prepare the magnetic nanoparticles for DNA detection.
Keywords: Fe3O4/CdTe nanoparticles, molecular beacon probe, fluorescence resonance energy transfer, Toxoplasma gondii DNA detection