A microtitre chemiluminescence sensor for detection of pyrethroids based on dual-dummy-template molecularly imprinted polymer and computational simulation.

The residues of pyrethroids in foods of animal origin are dangerous to the consumers, so this study presented a chemiluminescence sensor for determination of pyrethroids in chicken samples. A dual-dummy-template molecularly imprinted polymer capable of recognizing 10 pyrethroids was synthesized. The results of computation simulation showed that the specific 3D conformations of the templates had important influences on the polymer' recognition ability. The polymer was used to prepare a sensor on conventional 96-well microplates, and the sample solution was added into the wells for direct absorption. The absorbed analytes were initiated with the bis(2,4,6-trichlorophenyl)oxalate-H2 O2 -imidazole system, and the chemiluminescence intensity was used for analyte quantification. Results showed that one assay was finished within 12 min, and this sensor could be reused four times. The limits of detection for the 10 analytes were in the range o0.3-6.0 pg/ml, and the recoveries from the standards of fortified blank chicken samples were in the range 70.5-99.7%.

Determination of sulfonamides in meat with dummy-template molecularly imprinted polymer-based chemiluminescence sensor.

In this study, a molecularly imprinted polymer capable of recognizing 15 sulfonamides was first synthesized with sulfabenz as the dummy template. The calculation results from computation simulation showed that the specific 3D conformation of the template had an important influence on the polymer's recognition ability. Then, the polymer was used as recognition reagent to prepare a chemiluminescence sensor on a conventional 96-well microplate for the determination of the residues of 15 sulfonamides in meat (chicken and pork). Due to the 4-(imidazol-1-yl)phenol-enhanced luminol-H2O2 system, the limits of detection for the 15 analytes were in the range of 1.0-12 pg/mL. The recoveries from the standard fortified blank samples were in the range of 72.7-99%. Furthermore, one assay could be finished within 30 min, and the sensor could be reused 4 times. Therefore, this sensor could be used as a very useful tool for routine screening of residues of sulfonamides in meat samples. Graphical abstract Assay procedures of the molecularly imprinted polymer-based chemiluminescence sensor for determination of sulfonamides.

Detection of chloramphenicol in chicken, pork and fish with a molecularly imprinted polymer-based microtiter chemiluminescence method.

In this study, 4-nitrotoluene (NT) was used as dummy template to synthesize a molecularly imprinted polymer that was highly specific for chloramphenicol. The polymer was coated in the wells of 96-well microplates as recognition reagent to develop a chemiluminescence method. The analyte solution and an enzyme-labelled hapten were added into the wells to perform competition, and the light signal was induced with a highly efficient luminol-H2O2-4-(imidazol-1-yl)phenol system. Then, the optimized method was used to determine chloramphenicol in meat (chicken, pork and fish), and the limit of detection (LOD) was 5.0 pg g-1. Furthermore, the polymer-coated plate could be reused four times, and one test could be finished within 20 min. The recoveries from the standard fortified blank meat samples were in the range of 71.5-94.4%. Therefore, this method could be used as a useful tool for routine screening the residue of chloramphenicol in meat samples.

Dummy molecularly imprinted polymer based microplate chemiluminescence sensor for one-step detection of Sudan dyes in egg.

The objective of this study is to report a molecularly imprinted polymer-based chemiluminescence method for determination of Sudan dyes. A dummy-template molecularly imprinted polymer capable of recognizing seven Sudan dyes was first synthesized and its recognition mechanism was studied by using computation simulation method. The polymer was coated in the wells of conventional microplate to prepare a chemiluminescence sensor and the assay process consisted of only one sample-loading step prior to signal acquisition. The optimized sensor was used to determine the seven dyes in egg yolk and the results were confirmed with a high performance liquid chromatography. Results showed that this sensor achieved ultrahigh sensitivity (1.0-5.0 pg/mL), rapid assay process (10 min) and satisfactory recovery (70.5%-92.2%). Furthermore, the sensor could be reused for 5 times. Therefore, this sensor could be used as a useful tool for screening the residues of Sudan dyes in egg.

Dummy template molecularly imprinted polymer for solid phase extraction of phenothiazines in meat based on computational simulation.

The 3D structures of two dummy templates and four phenothiazine drugs were studied by using computational simulation method. Then the two dummy templates were used to synthesize two molecularly imprinted polymers respectively. Results showed that the recognition abilities of the two polymers were consistent with the theoretical calculation. Then a solid phase extraction column was developed for extraction of the four phenothiazines in meat (pork, chicken) followed by determination with high performance liquid chromatography. The column showed high adsorption capacities (850-962ng analyte per milligram of polymer) and high recoveries (93-98%) to the four drugs, and could be recycled for sixty times. The limits of detection were in the range of 1.0-10ng/g, and the recoveries from the fortified blank samples were in the range of 70.3-96.1%. This is the first study reporting the use of molecularly imprinted polymer-based method for determination of phenothiazines residues in foods.