Continuous and real‐time sensoring has received much attention in biomarker monitoring, toxicity assessment, and therapeutic agent tracking. However, its on‐site application is seriously limited by several stubborn defects including liability to fouling, signal drifting, short service life, poor repeatability, etc. Additionally, most current methods require extra sample pretreatment, delaying timely acquisition of testing results. To address these issues, MXene‐Ti3C2Tx based screen‐printed electrode incorporated with a dialysis microfluidic chip is constructed for a direct and continuous multicomponent analysis of whole blood. Dual‐function of MXene is developed and allows for simultaneous quantification of different target compounds through one device. Importantly, ratiometric sensing tactic is easily implemented in the system, which greatly alleviates signal drifting. As a proof of concept, this novel sensor is applied in hemodialysis, and continuous assay of urea, uric acid, and creatinine levels in human blood is realized. This work paves a new path for 2D MXene in biomedical and sensing applications.

Electrochemical nanosensors based on nanoporous gold leaf (NPGL) and molecularly imprinted polymer (MIP) are developed for pharmaceutical analysis by using metronidazole (MNZ) as a model analyte. NPGL, serving as the loading platform for MIP immobilization, possesses large accessible surface area with superb electric conductivity, while electrochemically synthesized MIP thin layer affords selectivity for specific recognition of MNZ molecules. For MNZ determination, the hybrid electrode shows two dynamic linear range of 5 × 10−11 to 1 × 10−9 mol L−1 and 1 × 10−9 to 1.4 × 10−6 mol L−1 with a remarkably low detection limit of 1.8 × 10−11 mol L−1 (S/N = 3). In addition, the sensor exhibits high binding affinity and selectivity towards MNZ with excellent reproducibility and stability. Finally, the reliability of MIP-NPGL for MNZ detection is proved in real fish tissue samples, demonstrating the potential for the proposed electrochemical sensors in monitoring drug and biological samples.

Ratiometric electrochemical sensors coupled with an intrinsic built-in correction have received much attention in biochemical analysis, which can effectively avoid potential impacts from both intrinsic and extrinsic factors. However, the complex modification procedure and the unstable reference signal limit development and application of ratiometric sensing. To address these issues, we proposed a novel ratiometric electrochemical platform based on MXene. Introduction of built-in correction was realized via simple one-step incubation of MXene in solution containing the reference molecule methylene blue (MB), and their firm electrostatic interaction ensures the strong adsorption capability of MXene toward MB. Remarkable enhancement in repeatibility and stability compared with nonratio sensor was proved by detecting the model analyte piroxicam. Furthermore, compatibility of the ratio sensor was demonstrated by integrating copper nanoparticles (CuNPs) into the platform. It turned out that sensing performance of the hybrid electrochemical sensor was significantly improved owing to synergistic effect of MXene and CuNPs, where the former affords a large specific surface area as well as quick electron transport, and the latter possess decent electrical catalytic ability. In all, the proposed ratiometric sensor based on MXene features easy preparation, superb reproducibility, robustness, and broad applicability, affording the platform highly competitive and reliable in the determination of a wide range of substances.

Two-dimensional (2D) transition-metal/metal chalcogenides including MoS2, MoSe2, WS2, SnS2, etc. have shown considerable potential for the fabrication of gas sensors for NO2 detection. However, these sensors usually suffer from sluggish and incomplete recovery at room temperature, and their sensitivities are limited by presorbed O2. In this work, a novel optoelectronic gas sensor based on direct-bandgap InSe nanosheets was demonstrated. Because of the excellent photoelectric and sensing properties in few-layer InSe, detection of NO2 at room temperature was realized. Ultrahigh and reversible responses were obtained under ultraviolet (UV) light illumination, and the limit of detection (0.98 ppb) was ∼40 times lower than that observed without UV light. Furthermore, the effects of O2 and H2O molecules on sensor performance were fully studied through experiments and density functional theory. Some new mechanisms of NO2 detection in high relative humidity conditions under UV illumination were proposed, including regulation of proton transfer and induction of H2O2 reduction. In all, this work not only broadens the application field of 2D InSe, but also demonstrates the potential prospect of detecting ppb-level NO2 in complex circumstances such as human breath by using 2D material-based sensors with light activation.

A novel carbon foam (CF) was preparedviaphysically activating banana peel and applied for adsorbing various heavy metal ions including Cu2+, Pb2+, Cd2+and Cr6+in aqueous solution.

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Metronidazole-imprinted polymers with superior recognition properties were prepared by a novel strategy called distillation-precipitation polymerization. The as-obtained polymers were characterized by Fourier-transform infrared spectroscopy, laser particle size determination and scanning electron microscopy, and their binding performances were evaluated in detail by static, kinetic and dynamic rebinding tests, and Scatchard analysis. The results showed that when the fraction of the monomers was 5 vol% in the whole reaction system, the prepared polymers afforded good morphology, monodispersity, and high adsorption capacity and excellent selectivity to the target molecule, metronidazole. The optimal binding performance is 12.41 mg/g for metronidazole just before leakage occurred and 38.51 mg/g at saturation in dynamic rebinding tests. Metronidazole-imprinted polymers were further applied as packing agents in solid-phase extraction and as chromatographic filler, both of which served for the detection of metronidazole in fish tissue. The results illustrated the recoveries of spiked samples ranged from 82.97 to 87.83% by using molecularly imprinted solid-phase extraction combined with a C18 commercial column and 93.7 to 101.2% by directly using the polymer-packed chromatographic column. The relative standard deviation of both methods was less than 6%.

Various antibiotics have been extensively used to treating infectious diseases in hospitals. In this study, the abundance and diversity of antibiotics and antibiotic resistance genes (ARGs) were observed in the wastewater samples from five hospitals in Xinjiang, China. The total concentrations of tetracyclines, sulphonamides, and quinolones in hospital influents ranged from 363.4 to 753.3 ng/L, 285.5 to 634.9 ng/L, and 1355.8 to 1922.4 ng/L, respectively. However, the removal efficiency of tetracyclines, sulphonamides, and quinolones in wastewater treatment processes ranged from 72.4 to 79.3 %, 36.0 to 52.2 %, and 45.1 to 55.4 %, respectively. The contamination levels of the selected ARGs varied in all wastewater samples. The highest relative concentrations of sul1, sul2, tetQ, and qnrS were significantly higher than those of other ARGs in this study. Significant positive correlations between the relative abundance of partial ARGs and concentrations of certain antibiotics were observed in hospital wastewaters. Results show that integrons played an important role in disseminating and distributing ARGs in microorganism systems. Furthermore, strong correlations were observed between tetQ, sulphonamide resistance genes (except sulA) and intI1. This study aimed to determine the contamination levels of antibiotics and ARGs and analyze the relationships among ARGs, and antibiotics and integron genes in hospital wastewaters.