Integration of mesostructured silica with bathophenanthroline into a porous alumina membrane by one-pot synthesis method

Abstract

An integration of mesostructured silica containing a chelating reagent, bathophenanthroline (Bphen), into a porous alumina membrane by a one-pot synthesis method is demonstrated, and the integrated membrane is applied for detection of Fe(II). The integration is performed by spotting a precursor solution on a porous alumina membrane under moderate aspiration. The precursor solution contains Pluronic F127 as a template surfactant, tetraethoxysilane as a silica source, and Bphen as a chelating reagent. After the integration, columnar mesostructured silica is formed inside the alumina pore, and the pore structure of columnar mesostructured silica is circular or concentric three-layer stacked-doughnuts structure when the concentration of Bphen in the precursor solution is below 15 mM. On the other hand, the distinct pore structure is not obtained when the concentration of Bphen is high (⩾20 mM). The integrated membrane can be used to detect ca. 10 μM of Fe(II) in an aqueous solution. This indicates that the integration of mesostructured silica containing an organic ligand into a porous alumina membrane is useful for developing a membrane-based analytical chip.