Construction Of Phenobarbital Molecular Imprinted Piezoelectric Sensor And Its Application In Animal Derived Food Detection

Phenobarbital?PHN?belongs to a barbiturate sedative and sleeping pill.Due to it can promote the animal growth,the PHN could be abusively used as the feed additives in some enterprises,livestock,and poultry farms.Therefore,it leads to the residue of PHN exceeds standard in livestock and poultry farms.It could harm to the physiological function of the human body,and even causes allergy and malformation.Along with the strict supervision and management for feed and food safety of the state,it is necessary to prepared a new solid phase extraction material to the accurate enrich and separate the PHN from complex matrix of food sample.Molecular imprinting polymers?MIPs?are novel high polymer materials,and their imprinting moledules and template moledules could be matched in spatial structure and binding site.Because of memory effects on the shape size and functional group of imprinted molecular,the trace residual of determinand can be selectively adsorbed from the complex matrix composition of food samples.Consequently,MIPs with the specific adsorption have been widely used in food safely monitoring and the other fields.Recent years,to improve the efficiencies of research and development,more and more researchers use the simulated calculation to the design of the MIPs.It can supply more accurately theoretical guidance for the preparation of MIPs.All the calcultions are performed by using the quantum chemical M062X method of Gaussian 09 Program review Revision A.02 software.Here PHN was as the imprinted molecular,and 4-vinyl pyridine?4-VPY?,acrylamide?AM?,methacrylic acid?MAA?,and itaconic Acid?IA?were as the functional monmers.Diethyiene benzene?DVB?,ethylene glycol dimethacrylate?EGDMA?,pentaerythritol triacrylate?PETA?,and trihydroxymethylpropol trimethylacrtlate?TRIM?are as the cross-linking agents.Water,acetonitrile,methanol,tetrahydrofuran,chloroform,and toluene were as the solvents.The configurations of PHN and functional monomers imprinted self-assembly system were simulated.The best functional monomer of the stable complex,the optimized cross-linking agents,and the proper solvent were selected.The atomic theory in molecules?AIM?was used to reveal the essence of imprinting for PHN.The selectivity of PHN stable complex was also discussed.The simulated results show that the PHN and IA interact via hydrogen bonds.When the molar ratio of PHN and IA is 1:7 and the TRIM is as the cross-linking agent,the ordered complexes of PHN and IA have the lowest binding energy and the most configuration in toluene solvent.With the guidance of the theoretical research,the PHN-MIPs were prepared by the precipitation polymerization,when the IA was used as the functional monomer,TRIM was as the cross-linking agent,and the methanol was as the solvent.Their properties and morphology were also evaluated.The results of static adsorption experiments show that the maximum apparent adsorption capacity(Q_max)and the dissociation equilibrium constant?K_d?were 16.02mg/g and 94.97 mg/L.The dynamic adsorption results show that when the adsorption time reaches 450 min,the adsorption capacity is maximum and the adsorption rate no longer changes.The infrared analysis shows that the band not only widens,but also has a red shift.It proves the formation of hydrogen bonds.The prepared PHN-MIPs and NIPs are spherical with an average diameter of 240 nm and 180 nm.And PHN-MIPs have favourable thermal stability at 280oC.When the polyvinyl chloride?PVC?is as embedding material and tetrahydrofuran is as solvent,the PHN-MIPs piezoelectric sensor has been constructed.Then it was applied to detect the PHN in meet samples.The results show that the sensor has the best response when the PH is7,the amount of PHN-MIPs is 150 mg,and the volume of coating amount is 20?L.The corresponding limit of detection?LOD?is 5.11 ng/mL.The recovery rate of PHN in meet samples is 94.64%⁹8.70%.