Fabrication of octahedral GO/UiO-67@PtNPs nanocomposites as an electrochemical sensor for ultrasensitive recognition of arsenic (III) in Chinese Herbal Medicine

Revealing the solid-solution interface interference behaviors between Cu2+ and As(III) via partial peak area analysis of simulations and experiments

The mutual interference in the sensing detection of heavy metal ions (HMIs) is considerably serious and complex. Besides, the co-existed ions may change the stripping peak intensity, shape and position of the target ion, which partly makes peak current analysis inaccurate. Herein, a promising approach of partial peak area analysis was proposed firstly to research the mutual interference. The interference between two species on their electrodeposition processes was investigated by simulating different kinetics parameters, including surface coverage, electro-adsorption, -desorption rate constant, etc. It was proved that the partial peak area is sensitive and regular to these interference kinetics parameters, which is favorable for distinctly identifying different interferences. Moreover, the applicability of the partial peak area analysis was verified on the experiments of Cu2+, As(III) interference at four sensing interfaces: glassy carbon electrode, gold electrode, Co3O4, and Fe2O3 nanoparticles modified electrodes. The interference behaviors between Cu2+ and As(III) relying on solid-solution interfaces were revealed and confirmed by physicochemical characterizations and kinetics simulations. This work proposes a new descriptor (partial peak area) to recognize the interference mechanism and provides a meaningful guidance for accurate detection of HMIs in actual water environment.

Three-Dimensional Electrochemical Sensors for Food Safety Applications

Considering the increasing concern for food safety, electrochemical methods for detecting specific ingredients in the food are currently the most efficient method due to their low cost, fast response signal, high sensitivity, and ease of use. The detection efficiency of electrochemical sensors is determined by the electrode materials' electrochemical characteristics. Among them, three-dimensional (3D) electrodes have unique advantages in electronic transfer, adsorption capacity and exposure of active sites for energy storage, novel materials, and electrochemical sensing. Therefore, this review begins by outlining the benefits and drawbacks of 3D electrodes compared to other materials before going into more detail about how 3D materials are synthesized. Next, different types of 3D electrodes are outlined together with common modification techniques for enhancing electrochemical performance. After this, a demonstration of 3D electrochemical sensors for food safety applications, such as detecting components, additives, emerging pollutants, and bacteria in food, was given. Finally, improvement measures and development directions of electrodes with 3D electrochemical sensors are discussed. We think that this review will help with the creation of new 3D electrodes and offer fresh perspectives on how to achieve extremely sensitive electrochemical detection in the area of food safety.

Progress and opportunities for metal-organic framework composites in electrochemical sensors

Metal-organic framework composites have the advantages of large surface area, high porosity, strong catalytic efficiency and good stability, which provide a great possibility of finding excellent electrode materials for electrochemical sensors. However, MOF composites still face various challenges and difficulties, which limit their development and application. This paper reviews the application of MOF composites in electrochemical sensors, including MOF/carbon composites, MOF/metal nanoparticle composites, MOF/metal oxide composites and MOF/enzyme composites. In addition, the application challenges of MOF composites in electrochemical sensors are summarized. Finally, the application prospect for MOF composites is considered to promote the synthesis of more MOF composites with excellent properties.

Ultra-sensitive detection of multiplexed heavy metal ions by MOF-derived carbon film encapsulating BiCu alloy nanoparticles in potable electrochemical sensing system

In this work, we report the development of a new type of highly active and stable Bi-based electrode material, i.e., BiCu metal-organic frames (MOF) derived carbon film (CF) encapsulating BiCu alloy nanoparticles (BiCu-ANPs) for electrochemical sensing. The integration of Bi with Cu to form BiCu-ANPs can improve their electrocatalytic activity as well as the acid resistance. Meanwhile, the carbon film that encapsulates BiCu-ANPs not only guarantees the BiCu-ANPs with high electrical conductivity and fast electrochemical kinetics but also effectively alleviates the volume change during the adsorption and desorption of heavy metal (HM) ions. Therefore, the as-obtained CF encapsulating BiCu-ANPs (BiCu-ANPs@CF) exhibits fully exposed active sites, facile charge transfer, high stability and conductivity, which gives rise to enhanced sensitivity and stability for the electrochemical detection of HM ions. When integrated into a potable electrochemical sensing system for simultaneous detection of Pb²⁺, Cd²⁺ and Zn²⁺, the BiCu-ANPs@CF modified electrode exhibits low detection limit (i.e., 0.081 ppb for Pb²⁺, 0.95 ppb for Cd²⁺, 35 ppb for Zn²⁺), wide detection range (i.e., 0.5-700 ppb for Pb²⁺, 5-900 ppb for Cd²⁺, 150-600 ppb for Zn²⁺) and good anti-interference. Finally, the system has been used for on-site detection of multiplexed HM ions in human biological liquids and environmental water with a good spiked recovery rate, which demanstrates its promise application in the future for on-site monitoring of human health and pollutants in water quality.

The safety of Chinese medicine: A systematic review of endogenous substances and exogenous residues

BACKGROUND

Safety and toxicity have become major challenges in the internationalization of Chinese medicine. Inspite of its wide application, security problems of Chinese medicine still occur from time to time, raising widespread concerns about its safety. Most of the studies either only partially discussed the intrinsic toxicities or extrinsic harmful residues in Chinese medicine, or briefly described detoxification and attenuation methods. It is necessary to systematically discuss Chinese medicine's extrinsic and intrinsic toxic components and corresponding toxicity detoxification or detection methods as a whole.

PURPOSE

This review comprehensively summarizes various toxic components in Chinese medicine from intrinsic and extrinsic. Then the corresponding methods for detoxification or detection of toxicity are highlighted. It is expected to provide a reference for safeguards for developing and using Chinese medicine.

METHODS

A literature search was conducted in the databases, including PubMed, Web of Science,Wan-fang database, and the China National Knowledge Infrastructure (CNKI). Keywords used were safety, toxicity, intrinsic toxicities, extrinsic harmful residues, alkaloids, terpene and macrolides, saponins, toxic proteins, toxic crystals, minerals, heavy metals, pesticides, mycotoxins, sulfur dioxide, detoxification, detection, processing (Paozhi), compatibility (Peiwu), Chinese medicine, etc., and combinations of these keywords. All selected articles were from 2006 to 2022, and each was assessed critically for our exclusion criteria. Studies describe the classification of toxic components of Chinese medicine, the toxic effects and mechanisms of Chinese medicine, and the corresponding methods for detoxification or detection of toxicity.

RESULTS

The toxic components of Chinese medicines can be classified as intrinsic toxicities and extrinsic harmful residues. Firstly, we summarized the intrinsic toxicities of Chinese medicine, the adverse effects and toxicity mechanisms caused by these components. Next, we focused on the detoxification or attenuation methods for intrinsic toxicities of Chinese medicine. The other main part discussed the latest progress in analytical strategies for exogenous hazardous substances, including heavy metals, pesticides, and mycotoxins. Beyond reviewing mainstream instrumental methods, we also introduced the emerging biochip, biosensor and immuno-based techniques.

CONCLUSION

In this review, we provide an overall assessment of the recent progress in endogenous toxins and exogenous hazardous substances concerning Chinese medicine, which is expected to render deeper insights into the safety of Chinese medicine.