title: Molecularly imprinted quartz crystal microbalance sensor based on poly(o-aminothiophenol) membrane and Au nanoparticles for ractopamine determination.
abstract: A molecularly imprinted quartz crystal microbalance (QCM) sensor for ractopamine (RAC) detection was developed by electrodepositing a poly-o-aminothiophenol membrane on an Au electrode surface modified by self-assembled Au nanoparticles (AuNPs). The modified electrodes were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. This molecularly imprinted QCM sensor showed good frequency response in RAC binding measurements and the introduction of AuNPs demonstrated performance improvements. Frequency shifts were found to be proportional to concentration of RAC in the range of 2.5×10(-6) to 1.5×10(-4) mol L(-1) with a detection limit of 1.17×10(-6) mol L(-1) (S/N=3). The sensor showed a good selective affinity for RAC (selectivity coefficient >3) compared with similar molecules and good reproducibility and long-term stability. This research has combined the advantages of high specific surface area of AuNPs, high selectivity from molecularly imprinted electrodeposited membrane and high sensitivity from quartz crystal microgravimetry. In addition, the modified electrode sensor was successfully applied to determine RAC residues in spiked swine feed samples with satisfactory recoveries ranging from 87.7 to 95.2%.
authors: Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology, Tianjin 300457, China.
authors: Ling-Jie
authors: LJ
authors: Kong
authors: Ming-Fei
authors: MF
authors: Pan
authors: Guo-Zhen
authors: GZ
authors: Fang
authors: Xin-lei
authors: XL
authors: He
authors: Yu-kun
authors: YK
authors: Yang
authors: Jie
authors: J
authors: Dai
authors: Shuo
authors: S
authors: Wang
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D006046:Gold / Q000737:chemistry*; D006133:Growth Substances / Q000032:analysis*; D057230:Limit of Detection; D054802:Molecular Imprinting; D053758:Nanoparticles / Q000737:chemistry; D010627:Phenethylamines / Q000032:analysis*; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods*; D013552:Swine
chemical_list: D000814:Aniline Compounds; D006133:Growth Substances; D010627:Phenethylamines; C005464:2-aminothiophenol; C060897:ractopamine; D006046:Gold
keywords: Au nanoparticles; Molecularly imprinted electrodeposited membrane; Quartz crystal microbalance sensor; Ractopamine