Highly selective molecularly imprinted-electrochemiluminescence sensor based on perovskite/Ru(bpy)32+ for simazine detection in aquatic products.

A novel molecularly imprinted electrochemiluminescence (MIECL) sensor based on the luminescence of molecularly imprinted polymer-perovskite (MIP-CsPbBr3) layer and Ru(bpy)32+ was fabricated for simazine detection. MIP-CsPbBr3 layers were immobilized onto the surface of glassy carbon electrode as the capture and signal amplification probe, and Ru(bpy)32+ and co-reactant tripropylamine exhibited stronger electrochemiluminescence (ECL) emission. Under optimal conditions, the ECL signal of the MIECL sensor was linearly quenched, with the logarithm of simazine concentration ranging from 0.1 µg/L to 500.0 µg/L, correlation coefficient of 0.9947, and limit of detection of 0.06 µg/L. The practicality of the developed MIECL sensor method for simazine determination in aquatic samples was validated. Excellent recoveries of 86.5 %-103.9 % with relative standard deviation below 1.6 % were obtained for fish and shrimp samples at three different spiked concentrations. The MIECL sensor exhibited excellent selectivity, sensitivity, reproducibility, accuracy, and precision for simazine determination in actual aquatic samples.

Effective removal matrix interferences by a modified QuEChERS based on the molecularly imprinted polymers for determination of 84 polychlorinated biphenyls and organochlorine pesticides in shellfish samples.

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure combined with GC-MS/MS detection approach using a dynamic multiple reaction monitoring (DMRM) mode was successfully applied for the simultaneous analysis of 84 polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in shellfish samples. The novel molecular imprinted polymers (MIPs) were synthesized by precipitation polymerization and characterized by Scanning electron microscopy, Brunauer-Emmett-Teller, Fourier transform infrared spectra and adsorption experiment. The MIPs exhibited good adsorption capability to pigment coextractives in shellfish samples without the loss of analytes compared with other sorbents. Under optimal conditions, spiked experiments in sinonovacula, mussel, and clam at 10.0-100.0 µg/kg concentrations showed excellent recoveries ranging from 70% to 120% for all analytes with the relative standard deviations of <10%. The developed method showed good linearity with the correlation coefficient above 0.9980, and the limits of quantification were in the range of 0.01-9.02 µg/kg. The developed QuEChERS procedure combined with GC-MS/MS was successfully applied to 84 PCBs and OCPs residues detection in shellfish samples.

Development and application of a novel fluorescent nanosensor based on FeSe quantum dots embedded silica molecularly imprinted polymer for the rapid optosensing of cyfluthrin.

A novel molecularly imprinted silica layer appended to FeSe quantum dots (MIP-FeSe-QDs) was fabricated and utilized as a recognition element to develop a selective and sensitive fluorescent nanosensor for cyfluthrin (CYF) determination. The MIP-FeSe-QDs were characterized by fluorescence spectrometry, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Excellent selectivity and high sensitivity of MIP-FeSe-QDs to CYF molecules were observed based on the fluorescence quenching of FeSe-QDs. Under optimal conditions, a good linear relationship was found between fluorescence quenching effect and increased CYF concentration within 0.010-0.20mg/L, with a correlation coefficient of 0.9911. The practicality of the developed sensor method for CYF detection in fish and sediment samples was further validated. Good recoveries ranging from 88.0% to 113.9% with<6.8% relative standard deviations were obtained. The detection limits of CYF in sediment and fish samples were 1.3 and 1.0µg/kg, respectively. This study established a novel, rapid fluorescent nanosensor detection method based on MIP-QDs for successfully analyzing CYF in fish and sediment samples.

Selective and sensitive determination of cypermethrin in fish via enzyme-linked immunosorbent assay-like method based on molecularly imprinted artificial antibody-quantum dot optosensing materials.

Molecularly imprinted silica layers appended to quantum dots (MIP-QDs) with customized selective artificial recognition sites were fabricated in this study by optimizing the ratio of the functional monomer to the template. Scanning electron microscopy, transmission electron microscopy, Brunauer­emmett­teller, Fourier transform infrared spectroscopy, and selectivity assay analyses were also performed. Results demonstrated that the selective fluorescence quenching properties of MIP-QDs toward cypermethrin (CYP) are due to strong interactions between these molecules. An enzyme-linked immunosorbent assay (ELISA)-like method based on the MIP-QDs was established under optimal conditions. The fluorescence quenching observed from this method showed a linear relationship with CYP concentration over the range of 0.05­60.0 mg/kg with a correlation coefficient of 0.9838. Good recovery (82.7­92.4%) and a relative standard deviation of less than 10.1% were obtained from fish samples spiked with three levels of CYP. This method also demonstrated a low detection limit of 1.2 µg/kg. The ELISA-like method based on MIP-QDs can be successfully employed to detect residual of CYP in fish samples.

[Secondary productivity of macrobenthos in rocky intertidal zone of Yushan Islands, Zhejiang Province].

In order to understand the current status of macrobenthos in intertidal zone of Yushan Islands, macrobenthos samples were collected from 5 sections in the intertidal zone in four seasons from March 2009 to January 2010, with the density, biomass, secondary productivity, and P/B value of the macrobenthos investigated by using Brey's empirical formula. The mean density of the marobenthos was 1419.5 ind x m(-2), mean biomass in ash free dry mass (AFDM) was 565.53 g x m(-2), mean annual secondary productivity was 285.58 g x m(-2) x a(-1) (AFDM), and mean annual P/B value was 0.51. The secondary productivity was mainly affected by mollusca and gastropda, with five critical species Septifer virgatus, Modiolus modiolus, Serpulorbis imbricata, Tetraclita japonica, and T. squamosa contributed 84.0% of the total. The P/B value in the study area was lower than that in other sea areas, showing that the generation turnover rate of the macrobenthos in the intertidal zone of Yushan Islands was slower, and the community structure was more stable.

[Macrobenthic faunal diversity in Xiangshan Bay].

In order to understand the community pattern and biodiversity of macrobenthic fauna in Xiangshan Bay, an eight cruises survey was made at thirteen stations of the Bay from July 2006 to August 2007, with the dominant species composition, richness, biomass, secondary productivity, and P/B value of macrobenthic fauna investigated, and the species diversity of the macrobenthic fauna analyzed. A total of 123 macrobenthos species were recorded, including 48 species Mollusc, 33 species Crustacea, 12 species fish, 12 species annelid polychaete, 8 species echinoderms, and some coelenterates and nematodes. The dominant species were more concentrated, and the dominance index was higher. The average secondary productivity of the macrobenthic fauna was 16.70 g x m(-2) x a(-1), and the average P/B value was 0.60. There existed distinct variations (P < 0.01) in the species richness index (d), evenness index (J), Simpson's diversity index (D), and Shannon diversity index (H) among different survey stations, and distinct variations (P < 0.01) in the indices except evenness index (J) between years.