A series of hybrid TiO2 nanoparticles containing chelating molecules based on diethylenetriaminepentaacetic acid (DTPA) moiety have been synthesized and thoroughly characterized by TEM, SEM, powder XRD, FT-IR, C-13 solid-state MAS NMR, CHN elemental analysis, and BET. The surface modification of these nano-materials was established by coupling accessible amino group functions of TiO2/PABA supports (para-amino benzoic acid, PABA) with either modified-monoanhydride or -carboxylic acid compounds. The extraction percentages, distribution coefficients (Kd(Gd)), capacities (C-Gd) and ionic selectivities (S-Gd/La) of these surface-functionalized nano-structured materials between lanthanum and gadolinium in acidic range of pH were investigated. (C) 2015 Elsevier B.V. All rights reserved.