A smartphone-assisted photoelectrochemical POCT method via Z-scheme CuCo2S4/Fe3O4 for simultaneously detecting co-contamination with microplastics in food and the environment.

As emerging contaminants, microplastics threaten food and environmental safety. Dibutyl phthalate (DBP, released from microplastics) and benzo[a]pyrene (BaP, adsorbed on microplastics) coexisted in food and the environment, harming human health, requesting a sensitive and simultaneous testing method to monitor. To address current sensitivity, simultaneousness, and on-site portability challenges during dual targets in complex matrixes, CuCo2S4/Fe3O4 nanoflower was designed to develop a smartphone-assisted photoelectrochemical point-of-care test (PEC POCT). The carrier transfer mechanism in CuCo2S4/Fe3O4 was proven via density functional theory calculation. Under optimal conditions, the PEC POCT showed low detection limits of 0.126, and 0.132 pg/mL, wide linearity of 0.001-500, and 0.0005-50 ng/mL for DBP and BaP, respectively. The smartphone-assisted PEC POCT demonstrated satisfied recoveries (80.00%-119.63%) in real samples. Coherent results were recorded by comparing the PEC POCT to GC-MS (DBP) and HPLC (BaP). This novel method provides a practical platform for simultaneous POCT for food safety and environment monitoring.

Molecularly imprinted polymers prepared from a single cross-linking functional monomer for solid-phase microextraction of estrogens from milk.

In this work, a single cross-linking functional monomer, 2,5-divinylterephthalaldehyde, was designed and synthesized to simplify the preparation of molecularly imprinted polymers (MIPs). In the presence of estradiol as a template, MIPs were successfully prepared using 2,5-divinylterephthalaldehyde along with a solvent and initiator. This method reduced most of the complex variables encountered in the traditional synthesis. Characterization of the morphology and structure of the MIPs was performed by scanning electron microscopy, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller analysis. Compared with non-imprinted polymers, the MIPs had higher adsorption capacities for five estrogens with imprinting factors above 2.9. The MIPs had high extraction efficiencies, good functional properties, long lifetimes, and good reproducibility, which made them suitable for solid-phase microextraction (SPME). Coupled with ultra-high performance liquid chromatography tandem mass spectrometry, the MIP-based fibers were applied to SPME for the analysis of five estrogens in milk samples. Under the best conditions, the established method had a wide linear range (0.5-10000 ng kg-1), low limits of detection (0.08-0.26 ng kg-1) and quantification (0.26-0.87 ng kg-1), good precision (3.2-8.1%, n = 6), and fiber-to-fiber reproducibility (4.3%-8.8%, n = 3). The MIPs-based fibers can be reused at least 60 times without apparent loss of extraction efficiency. Finally, this method was applied to the determination of target estrogens in milk samples with satisfactory relative recoveries (84.3%-105%, relative standard deviation ≤ 7.8%).

Big data analysis for evaluating bioinvasion risk.

BACKGROUND: Global maritime trade plays an important role in the modern transportation industry. It brings significant economic profit along with bioinvasion risk. Species translocate and establish in a non-native area through ballast water and biofouling. Aiming at aquatic bioinvasion issue, people proposed various suggestions for bioinvasion management. Nonetheless, these suggestions only focus on the chance of a port been affected but ignore the port's ability to further spread the invaded species. RESULTS: To tackle the issues of the existing work, we propose a biosecurity triggering mechanism, where the bioinvasion risk of a port is estimated according to both the invaded risk of a port and its power of being a stepping-stone. To compute the invaded risk, we utilize the automatic identification system data, the ballast water data and marine environmental data. According to the invaded risk of ports, we construct a species invasion network (SIN). The incoming bioinvasion risk is derived from invaded risk data while the invasion risk spreading capability of each port is evaluated by s-core decomposition of SIN. CONCLUSIONS: We illustrate 100 ports in the world that have the highest bioinvasion risk when the invaded risk and stepping-stone bioinvasion risk are equally treated. There are two bioinvasion risk intensive regions, namely the Western Europe (including the Western European margin and the Mediterranean) and the Asia-Pacific, which are just the region with a high growth rate of non-indigenous species and the area that has been identified as a source for many of non-indigenous species discovered elsewhere (especially the Asian clam, which is assumed to be the most invasive species worldwide).

Optimal temperature control of tissue embedded with gold nanoparticles for enhanced thermal therapy based on two-energy equation model.

Thermal therapy is a very promising method for cancer treatment, which can be combined with chemotherapy, radiotherapy and other programs for enhanced cancer treatment. In order to get a better effect of thermal therapy in clinical applications, optimal internal temperature distribution of the tissue embedded with gold nanoparticles (GNPs) for enhanced thermal therapy was investigated in present research. The Monte Carlo method was applied to calculate the heat generation of the tissue embedded with GNPs irradiated by continuous laser. To have a better insight into the physical problem of heat transfer in tissues, the two-energy equation was employed to calculate the temperature distribution of the tissue in the process of GNPs enhanced therapy. The Arrhenius equation was applied to evaluate the degree of permanent thermal damage. A parametric study was performed to investigate the influence factors on the tissue internal temperature distribution, such as incident light intensity, the GNPs volume fraction, the periodic heating and cooling time, and the incident light position. It was found that period heating and cooling strategy can effectively avoid overheating of skin surface and heat damage of healthy tissue. Lower GNPs volume fraction will be better for the heat source distribution. Furthermore, the ring heating strategy is superior to the central heating strategy in the treatment effect. All the analysis provides theoretical guidance for optimal temperature control of tissue embedded with GNP for enhanced thermal therapy.