Carboxyl was formed on the surface of glassy carbon electrode(GCE) by electrochemical oxidation. Ethylenediamine(En) was used as the arm molecule to link carboxyl with dsDNA using 1-ethyl-3-(3-dimethylaminopropyl)-car...Carboxyl was formed on the surface of glassy carbon electrode(GCE) by electrochemical oxidation. Ethylenediamine(En) was used as the arm molecule to link carboxyl with dsDNA using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride(EDC) and N-hydroxysuccinimide(NHS) as the activators to prepare dsDNA modified electrode(dsDNA/En/GCE). It was shown that dsDNA could be covalently immobilized on the surface of GCE. ssDNA modified electrode(ssDNA/En/GCE) was obtained via the thermal denaturation of dsDNA/En/GCE. The dsDNA/En/GCE and ssDNA/En/GCE were characterized by voltammetry with methylene blue(MB) as the indicator. The results indicated that the currents of the redox peaks of MB at ssDNA/En/GCE were larger than those at dsDNA/En/GCE, and the currents of the redox peaks at En/GCE were the smallest. The peak-currents of MB at the DNA modified electrode had good reproducibility after multi-denaturation and hybridization cycles.展开更多
The DNA magnetic nanoparticles are poten-tially useful in isolating and purifying DNA or RNA, direct-ing-target-medicines, the development of DNA biosensors and biochips. Surface functionalized magnetic nanoparticles ...The DNA magnetic nanoparticles are poten-tially useful in isolating and purifying DNA or RNA, direct-ing-target-medicines, the development of DNA biosensors and biochips. Surface functionalized magnetic nanoparticles with monodispersed shape and size were prepared by coating nano-sized g-Fe2O3 with silica in reverse microemulsion, and then thiol-compounds were immobilized onto the magnetic nanoparticles. After immobilizing oligoDNA modified with thiol-disulfide on the surface of the fictionalized magnetic nanoparticles, we obtained DNA-magnetic nanoparticles. The efficiency of the single-linking probes loading at the surfaces of magnetic nanoparticles was examined via hy-bridization experiment. Surface-enhanced Raman scattering methods were also effectively applied to observing the immobilization and hybridization processes mentioned above. The results demonstrated oligoDNA being availably connected to the surface of the magnetic nanoparticles.展开更多
文摘Carboxyl was formed on the surface of glassy carbon electrode(GCE) by electrochemical oxidation. Ethylenediamine(En) was used as the arm molecule to link carboxyl with dsDNA using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride(EDC) and N-hydroxysuccinimide(NHS) as the activators to prepare dsDNA modified electrode(dsDNA/En/GCE). It was shown that dsDNA could be covalently immobilized on the surface of GCE. ssDNA modified electrode(ssDNA/En/GCE) was obtained via the thermal denaturation of dsDNA/En/GCE. The dsDNA/En/GCE and ssDNA/En/GCE were characterized by voltammetry with methylene blue(MB) as the indicator. The results indicated that the currents of the redox peaks of MB at ssDNA/En/GCE were larger than those at dsDNA/En/GCE, and the currents of the redox peaks at En/GCE were the smallest. The peak-currents of MB at the DNA modified electrode had good reproducibility after multi-denaturation and hybridization cycles.
基金supported by the Natural Science Foundation of Shanghai(Grant No.02ZA14068).
文摘The DNA magnetic nanoparticles are poten-tially useful in isolating and purifying DNA or RNA, direct-ing-target-medicines, the development of DNA biosensors and biochips. Surface functionalized magnetic nanoparticles with monodispersed shape and size were prepared by coating nano-sized g-Fe2O3 with silica in reverse microemulsion, and then thiol-compounds were immobilized onto the magnetic nanoparticles. After immobilizing oligoDNA modified with thiol-disulfide on the surface of the fictionalized magnetic nanoparticles, we obtained DNA-magnetic nanoparticles. The efficiency of the single-linking probes loading at the surfaces of magnetic nanoparticles was examined via hy-bridization experiment. Surface-enhanced Raman scattering methods were also effectively applied to observing the immobilization and hybridization processes mentioned above. The results demonstrated oligoDNA being availably connected to the surface of the magnetic nanoparticles.
