Voltammetric studies on the simple ion transfer (IT) behaviors of an important water-soluble B-vitamin, folic acid (FA), at the liquid-liquid (L-L) interface were firstly performed and then applied as a novel detection method for FA under physiological conditions. Meso-water-1,6-dichlorohexane (W-DCH) and meso-water-organogel interface arrays were built by using a hybrid mesoporous silica membrane (HMSM) with a unique structure of pores-in-pores and employed as the new platforms for the IT voltammetric study. In view of the unique structure of the HMSM, the impact of the ionic surfactant cetyltrimethylammonium bromide (CTAB), self-assembled within the silica nanochannels of the HMSM, was investigated. In particular, its effect on the IT voltammetric behavior and detection of FA at meso-L-L interface arrays was systematically examined by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and differential pulse stripping voltammetry (DPSV). It was found that all the voltammetric responses of CV, DPV, and DPSV and the corresponding detection limit of FA at such meso-L-L interface arrays are closely related to the CTAB in the HMSM. Significantly, the calculated detection limit of FA could be improved to 80 nM after the combination of the DPSV technique with the additional preconcentration of FA in the silica-CTAB nanochannels, achieved through an anion-exchange process between FA(-) and the bromide of CTAB in HMSM. This provides a new and attractive strategy for the detection of those biological anions.

To mimic the anion channels in biomembrane, a novel strategy based on the membrane-modified liquid/ liquid interface using anion-exchange membranes was firstly proposed to study simple ion transfer processes of highly hydrophilic anions at the modified liquid/liquid interface by employing voltammetric methods. Significantly, fascinating ion transfer phenomena were observed at the water/1,2dichloroethane (W/DCE) interface modified by a homogeneous anion-exchange membrane, including the remarkable extension of the polarization window; well-defined transfer waves of some highly hydrophilic anions, such as sulfate and nitrite; and an amazing positive-shift of their transfer potentials.According to both ion-exchange membrane models, a new mechanism based on the sieving effect and pre-dehydration in combination with electrostatic effects dominantly induced by the gel phase of anionexchange membrane on ion transfer reactions was preliminarily proposed to explain those fascinating ion transfer phenomena.

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An organic/inorganic hybrid mesoporous silica membrane (HMSM) composed of mesoporous silica rods in the channels of a polycarbonate (PC) membrane was rapidly synthesized by employing the microwaveassisted method combined with solvent extraction. As-synthesized HMSMs were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), N 2 adsorption-desorption, X-ray diffraction (XRD) and thermogravimetry (TG). The results indicated that silica rods with 200 nm diameter and 9 mm length grew in the confined spaces of the PC membrane. The average diameter of mesopores with partially ordered hexagonal mesostructure was about 6.0 nm. In addition, it was found that an enzyme with suitable size, such as horseradish peroxidase (HRP), could be immobilized inside the mesopores of HMSM through physical adsorption.

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