▎ 摘　　要

The nickel nanoparticles/graphene ( Ni/Gr) composite synthesized here was served as a novel matrix and adsorbent for highly efficient matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy ( MALDI-TOF MS) analysis of various pharmaceutical molecules and amino acids. In comparison with 2 ,5-dihydroxybenzoic acid ( DHB ) and the control substances ( Gr, Ni-1/Gr, Ni-5/Gr) , the Ni-2/Gr matrix exhibited excellent performances in detection of resveratrol, 6-gingerol and rutin under positive-ion mode, including low background noise, high ion intensity , high signal to noise ratio and wide linear range (0. 01-50 mu mol/L, 0. 2-50 mu mol/L and 0. 05-60 mu mol/L). Meanwhile, the low limit of detection ( LODs) of resveratrol, 6-gingerol and rutin were 0.0038 mu mol/L, 0.09 mu mol/L and 0.02 mu mol/L, respectively. Benefiting from high surface area, abundant mesoporous structures, lots of sp(2) structure, strong UV absorption and high saturation magnetization ( Ms) value, Ni-2/Gr composite also acted as a favorable adsorbent for effectively analysis of L-phenylalanine, L-tryptophan and L-tyrosine with magnetic enrichment. Further, the low concentration of L-tryptophan spiked in mice serum bio-samples was directly enriched.