A dual-emission ratiometric fluorescence capillary imprinted sensor based on metal-organic frameworks for sensitive detection of L-tyrosine

A novel dual-emission ratiometric fluorescence capillary imprinted sensor based on luminescence metal organic framework was fabricated firstly with high sensitivity and selectivity for chiral recognition of L-tyrosine. To construct the ratiometric fluorescence capillary imprinted sensor, the luminescence metal organic framework and near-infrared quantum dots silicon as fluorescence sources were embedded into the imprinted layer which was grown up on the inner surface of amino-modified capillary. In present of L-tyrosine, the blue fluorescence (424 nm) served as fluorescence response signal was quenched due to the inner filter effects between metal organic framework and L-tyrosine while the red fluorescence (688 nm) served as the reference signal was remained. With the linear range of 1.0 × 10−10~ 2.5 × 10−8 M, the ratiometric fluorescence capillary imprinted sensor was applied to detect L-tyrosine in actual sample successfully with the satisfactory recoveries of 99.07~101.18% and the detect limitation of 8.0 × 10−11 M, indicating great potential application for detecting L-tyrosine in actual samples. The sensor integrated the molecularly imprinted technology and fluorescence capillary method achieved sensitive and selective determination of L-tyrosine with micro volume reagent consumption (18 μl) which provided a route for trace detection.