Surface modification of MCM-41 and its application in DNA adsorption

Three types of MCM-41 absorbents, namely, Al3+–MCM-41, La3+–MCM-41, and Zn2+–MCM-41, were prepared through amine grafting, phosphonate modification, and metal ion chelation and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and N2 adsorption–desorption analysis. Results revealed that functionalized MCM-41 maintains the original structure of the molecular sieve and that the pore diameter and surface area are reduced compared with those of pure MCM-41. The adsorption behavior of DNA molecules on the surface of the modified molecular sieves was discussed according to the hard-soft acid–base (HSAB) principle. Experimental results showed that DNA purification could be effectively carried out on functionalized MCM-41 and that DNA is easily released by 3–4 mol L−1 NaCl solution. This study could be used as a general platform for future work on DNA adsorption and enrichment.

Three types of functionalized MCM-41 were synthesized through MCM-41 amino-grafting, phosphonate modification, and metal ion chelation and subsequently used for DNA enrichment. DNA adsorption capacity showed significant enhancement following MCM-41 modification.Figure optionsDownload as PowerPoint slide