Chiral salen Mn(III) complex-based enantioselective potentiometric sensor for L-mandelic acid

摘要

A new enantioselective potentiometric sensor containing chiral salen Mn(lll) as the chiral selector was designed for the assay of L-mandelic acid (l-MA). Optimized membrane electrodes displayed linear dynamic range from 1 x 10~(-5) to 1 x 10~(-1) mol L~(-1) with a detection limit of 7.2 x 10~(-6) mol L~(-1) and a Nern-stian response of -58.1 ±0.5mVdecade~(-1) towards l-MA within pH range 7.0-10.2. The potentiometric enantioselectivity coefficient (logK_(L,D)~(Pot)) of this sensor was -4.0, indicating that the chiral salen Mn(lll) complex-based electrode exhibited fairly good discrimination toward l-MA over counter isomer d-MA. The mechanism of chiral recognition for l-MA is discussed by using HF/STO-3G calculation method simulation.