金基质的固体表面荧光法测定痕量Mn^(2+)

Determination of Trace Mn^(2+) by Gold-Substrate Solid Surface Fluorescence

以金片作为固体基质,通过自组装方式把荧光物质1-萘胺乙酸(NAA)间接组装在金表面,制备具有荧光特性的NAA/Cys/Au自组装膜.利用在酸性介质中,Mn2+可使NAA/Cys/Au自组装膜表面荧光产生猝灭,且荧光猝灭程度和Mn2+浓度在5.0×10-6~3.0×10-5mol.L-1范围内呈现良好的线性关系,从而建立利用固体表面荧光检测Mn2+的新方法,其检测下限为9.64×10-7mol.L-1.荧光被Mn2+猝灭后的自组装膜,可在NaOH溶液中实现膜表面荧光的再生.

Fluorescent reagent 2-（1-naphthyl）aminoacetic acid （NAA） was assembled onto the gold surface via its electrostatic interaction with DL-cysteine （Cys） that was directly assembled on the gold surface via Au-S bond, gained the NAA/Cys/Au self-assembled bilayer membrane. We build a new method to determinate Mn^2＋ based on the reaction of NAA/Cys/Au self-assembled bilayer membrane with Mn^2＋ in hydrochloric acid medium. The fluorescence intensity was measured with excitation and emission wavelengths of 320 and 407 nm, respectively. The linear range for the determination of Mn^2＋ was 5.0×10^-6～3.0×10^-5mol·L^-1 This method shows a detection limit of 9. 61×10^-7 mol·L^-1. The fluorescence from NAA/Cys/Au self-assembled bilayer membrane can be easily regenerated in sodium hydroxide medium, and therefore the present report showed a reusable method for solid surface fluorescence determination.