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Human exposure to disinfection by-products (DBPs) primarily occurs through the consumption of drinking water.

Long-term atmospheric quality monitoring of PM2.5 and PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) was performed in Wuxi from 2016 to 2021. A total of 504 atmospheric PM2.5 samples were collected, and PM2.5-bound 16 PAHs were detected. The PM2.5 and ∑PAHs level decreased annually from 2016–2021, from 64.3 to 34.0 μg/m3 and 5.27 to 4.22 ng/m3, respectively. The benzo[a]pyrene (BaP) of 42% of the monitoring days in 2017 exceeded the recommended health-based standard of the European Union (EU) at 1ng/m3. Five- and six-ring PAHs, including benz[a]anthracene (Baa), benzo[k] fluoranthene (Bkf), BaP, and benzo[g,h,i]perylene (Bghi), were the dominant components, indicating a prominent petroleum, biomass, and coal combustion contribution by molecular diagnostic ratios and positive matrix factorization analysis. Statistically significant temporal and spatial distribution differences of PM2.5, and ∑PAHs were also found. The toxicity equivalent concentration (TEQ) was 0.70 for total PAHs and the TEQ of BaP (0.178) was the highest, followed by Bkf (0.090), dibenz[a,h]anthracene (Dah) (0.048), and indeno[1,2,3-cd]pyrene (Ind) (0.034). The medians of the incremental lifetime cancer risk (ILCR) for long-term exposure to PAHs were 2.74E-8, 1.98E-8, and 1.71E-7 for children, teenagers, and adults, respectively, indicating that the carcinogenic risk of PAHs pollution in air was acceptable to local residents in this area. Sensitivity analysis showed that BaP, Bkf, and Dah significantly contributed to carcinogenic toxicity. This research supplies comprehensive statistics on the local air persistent organic pollutants profile, helps to identify the principle pollution source and compounds, and contributes to the prevention of regional air pollution.

Water elements pollution has attracted public attention globally. Wuxi is located in East China, and its water source, Taihu Lake, has been severely polluted since 2007. Studies of elemental pollution profiles have yet to be conducted in this area. In this study, 56 water samples were collected in 2018, and 33 elements were determined using inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the levels of 33 elements ranged from 1.35 × 10

Highly red luminescent gold nanoclusters (AuNCs) have been prepared at physiological temperature by using glutathione (GSH) as a stabilizing and capping agent in aqueous media. The resultant AuNCs have been characterized by photoluminescence and X-ray photoelectron spectroscopy, transmission electron microscopy and FTIR. The AuNCs exhibit red fluorescence with a quantum yield of 3.1 %, and fluorescence is strongly quenched by copper(II) ion due to aggregation. This finding is exploited in a fluorometric assay for Cu(II) that has a 2.8 nM detection limit. The method was applied to the determination of Cu(II) ion in (spiked) mineral water and Tai Lake water. In addition, the AuNCs display a strongly temperature-dependent emission that can be used for optical determination of temperature in the 0 to 60 °C range. We finally show that the AuNCs are viable nanomaterials for (a) plain imaging of Hep-2 cells by laser scanning confocal microscopy, and for (b) intracellular imaging of Cu(II) and of temperature in Hep-2 cells and E. coli.

The aim of this study was to examine the qualitative and quantitative analysis of Pb2+ adsorption mechanisms performed with biochars derived from rice straw (RSBs), rice husk (RHBs) and saw dust (SDBs) at several pyrolysis temperatures (400-600 °C) in a fluidized bed system. Adsorption isotherms, kinetics, and desorption analysis were determined, and biochars were analyzed by X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope with Energy Dispersive Spectrometer (SEM-EDS) and Boehm titration method. The effect of minerals on Pb2+ adsorption, including precipitation and cation exchange, revealed increasing contribution of precipitation from a range of 4.13%-38.83% to a range of 34.08%-79.94% and decreasing effect of cation exchange from a range of 50.17%-69.75% to a range of 9.57%-43.47% with increasing pyrolysis temperature. However, it remained the dominant adsorption mechanism of all biochars (accounted for 69.49-89.52%). Especially, RSBs with quite high maximum adsorption capacity (qm) values (116-127.57 mgg-1) were mainly due to precipitation mechanism of Pb2+ adsorption, which exhibited better adsorption capacities than RHBs (25.15-30.40 mgg-1) and SDBs (21.81-24.05 mgg-1). Only with the fluidized bed shown in this study, 2.00t RSBs could be produced and the corresponding Pb2+ adsorption may reach 255.50kg per year depending on its maximum adsorption capacity under 500 °C pyrolysis temperature. The results suggest that RSBs produced in a fluidized bed reactor is a promising, cost-effective, engineered biochar for application of Pb2+ remediation in aqueous solutions.

We have developed a method for the determination of microcystin-leucine-arginine (MC-LR) in water samples that is based on the quenching of the fluorescence of bioconjugates between CdSe/CdS quantum dots (QDs) and the respective antibody after binding of MC-LR. The core-shell CdSe/CdS QDs were modified with 2-mercaptoacetic acid to improve water solubility while their high quantum yields were preserved. Monoclonal MC-LR antibody was then covalently bioconjugated to the QDs. It was found that the fluorescence intensity of the bioconjugates was quenched in the presence of MC-LR. A linear relationship exists between the extent of quenching and the concentration of MC-LR. Parameters affecting the quenching were investigated and optimized. The limit of detection is 6.9 × 10−11 mol L−1 (3σ). The method was successfully applied to the determination of MC-LR in water samples.

A simple and sensitive electrochemical immunosensor was designed for the determination of ferritin (FeAg, as a model) in human serum by using a nanogold hollow microsphere (NGHS)-functionalized interface as an immunosensing probe. The presence of NGHSs provided a congenial microenvironment with large surface coverage for the immobilization of ferritin antibodies (FeAb). The formation of the antibody-antigen complex by a simple one-step immunoreaction between the immobilized FeAb and FeAg in sample solution introduced a change of membrane charge on the surface of the immunosensing probe. Thus, local potential variations could be detected by potentiometry. Compared to conventional gold nanoparticle probes, the NGHS-modified immunosensors exhibit wide dynamic range from 1.0 to 500 ng·mL−1 toward FeAg, with a detection limit of 0.1 ng·mL−1 (at 3σ). The selectivity, reproducibility and stability of the immunosensors are acceptable. The assay was evaluated with clinical serum specimens (n = 25), and excellent correspondence with the reference enzyme-linked immunosorbent assay method was obtained.

A simple and portable electrochemical immunosensor for the detection of total prostate specific antigen (t-PSA) in human serum was developed using a double-layer nanogold particles and dendrimer-functionalized polyvinyl chloride (PVC) membrane as immunosensing interface. To fabricate such a multifunctional PVC electrode, an o-phenylenediamine-doped PVC membrane was initially constructed, then nanogold particles and poly(amidoamine) G4-dendrimer with a sandwich-type format were assembled onto the PVC membrane surface, and then t-PSA antibodies (anti-PSA) were adsorbed on the nanogold surface. The detection principle of the immunosensor is based on the change in the electric potential before and after the antigen-antibody interaction. The experimental conditions and the factors influencing the performance of the immunosensor were investigated. Under optimal conditions, the proposed immunosensor exhibits good electrochemical behavior in the dynamic range of 0.5–18 ng/mL relative to t-PSA concentration with a relative low detection limit of 0.1 ng/mL (S/N=3). The precision, reproducibility, and stability of the immunosensor are acceptable. In addition, 43 serum specimens were assayed by the as-prepared immunosensor, and consistent results were obtained in comparison with those obtained by the standard enzyme-linked immunosorbent assay (ELISA). Compared with the conventional ELISAs, the developed immunoassay system was simple and rapid without labeling and separation steps. Importantly, the immobilization and detection methodologies could be extended for the immobilization and detection of other biomarkers.

Quantum dots (QDs) are semiconductor fluorescent nanoparticles, which can be used for food safety or environmental monitoring with high sensitivity. This work demonstrates the feasibility of detecting clenuterol residue in pig urine using CdSe/CdS quantum dots as fluorescent labels based magnetic core/shell Fe3O4/Au nanoparticles (MCFN) as solid carriers. The detection of clenbuterol is carried out by a fluoroimmunoassay-based biosensor using competitive binding between conjugated clenbuterol antigen-CdSe/CdS QDs and free clenbuterol with immobilized clenbuterol antibodies on MCFN. This assay method allows for clenbuterol determination in a linear working range of 0.5-20000 pg mL(-1). It would provide a simple, rapid, and ultra-sensitive detection method for clenbuterol or other biomolecular analysis.