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 N-2 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. (C) 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.