A selective fluorescent bulk sensor for lutetium based on hexagonal mesoporous structures

A novel Lu3+ sensitive fluorescent chemosensor is constructed by preparation of 8-hydroxyquinoline functionalized mesoporous silica with ordered hexagonal array structure (SBA-SPS-Q). The new synthesis material demonstrated a selective interaction with Lu3+ ion, most probably because of the presence of the fluorophore part at its surface. Fluorescence studies revealed that the emission intensity of the Lu3+-bound mesoporous material increases significantly after addition of various concentrations of Lu3+, while the mono-, di-, trivalent cations result in either no changes or weak changes in fluorescent intensities. The enhancement of fluorescence is attributed to the strong covalent binding of Lu3+ ion, evident from the large binding constant value (2 × 106 M−1). The linear range of the fluorescent chemosensor covers a Lu3+ concentration from 1.6 × 10−7 to 2.6 × 10−6 M, with detection limit of 4.0 × 10−8 M. This chemosensor has been applied to determination of Lu3+ ion in some soil samples where domestic devices were stored.