Development and application of tricolor ratiometric fluorescence sensor based on molecularly imprinted nanoparticles for visual detection of dibutyl phthalate in seawater and fish samples.

A tricolor ratiometric fluorescence sensor was fabricated by mixing blue- and red-emission molecularly imprinted quantum dots (MIP-QDs) with green-emission quantum dots at the optimal ratio. The MIP-QDs were synthesized by coating CdSe/ZnS QDs in polymer by inverse microemulsion method. Compared with single-emission or dual-emission sensors, the tricolor ratiometric fluorescence sensor provided a wider range of color variations for visual DBP detection. The ratio fluorescence value I530/(I450 + I630) of the tricolor ratiometric fluorescence sensor linearly changed within the concentration of 2.0-20.0 × 103 µg/L DBP. The correlation coefficient was 0.9910, and the limits of detection were 1.0 µg/kg and 0.65 µg/L in fish and seawater, respectively. Meanwhile, the fluorescence color gradually changed from purple to plum to pink to salmon to yellowish green and finally to green. The recoveries of DBP in fish and seawater were 84.3 %-91.4 % and 88.3 %-110.3 %, respectively. Moreover, no obvious differences were observed between the detection results of the tricolor ratiometric fluorescence sensor and gas chromatography-tandem mass spectrometry. The tricolor ratiometric fluorescence sensor constructed herein provides an ideal choice for rapid and intuitive DBP detection in environmental and aquatic products.

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.

Probing the contamination characteristics, mobility, and risk assessments of typical plastic additive-phthalate esters from a typical coastal aquaculture area, China.

Contamination characteristics, equilibrium partitioning and risk assessment of phthalate esters (PAEs) were investigated in seawater, sediment and biological samples collected from the Xiangshan Bay area during an annual investigation between January and November 2019. PAE concentrations detected in the mariculture environment in surface seawater, sediment, and biological samples were 172-3365 ng/L, 190-2430 µg/kg (dry weight [dw]), and 820-4926 µg/kg (dw), respectively. The dominant congeners in different media included di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), and di(2-ethylhexyl) phthalate (DEHP). The inner bay and the bay mouth were the gathering area of PAEs and heavily influenced by the mariculture activities, river inputs, and anthropogenic activities. The bioaccumulation of PAEs demonstrated benthic feeding fishes with relatively high trophic levels concentrated high levels of phthalates. The mobility of PAEs in sediment-seawater showed that the transfer tendency of low-molecular weight species was from the sediment to the water, which was in contrast with those of high-molecular weight PAEs. DEHP, DiBP and DnBP had various degrees of ecological risks in the aquatic environment, whereas only the DiBP posed potential risks in sediments. The current assessment of carcinogenic and noncarcinogenic risks posed by fish consumption were within acceptable limits for humans.