Li Li Yanfang Xie Yanping Wang Xiaodi Yang Rong Fu Chen Ren Fang Shen. Study on nicotinamide adenine dinucleotide adsorbed at nano-boehmite-water and nano-corundum-water interfaces.Colloids and Surfaces B: Biointerfaces 2013 102: 398–404.

Abstract

In this study the adsorption behaviors of nicotinamide adenine dinucleotide (NAD⁺) on nano-boehmite (γ-AlOOH) and nano-corundum (γ-Al₂O₃) surfaces were investigated. The results showed that NAD⁺ was predominantly adsorbed at the boehmite-water and corundum-water interfaces in outer-sphere fashions by electrostatic interaction between NAD⁺ phosphate and surface hydroxyl groups. However the features of ATR-FTIR spectra suggested that some minor inner-sphere complex should be considered at low pH conditions on corundum surface which was consistent with the effect of NAD⁺ on dissolution rate of corundum. In addition the adsorption data well fitted with Langmuir and Freundlich isotherms on the boehmite and corundum surfaces respectively. Also the Gibbs adsorption energy was negative on the boehmite surface which indicated that the adsorption behavior was spontaneous.

Graphical Abstract