Lead(II) ion (Pb2+) contamination can be accumulated along the food chain and cause a serious threat to public health. Plenty of research effort has thus been devoted to the development of fast, sensitive and selective biosensors for monitoring Pb2+. Aptamer especially Pb2+ based DNAzymes (obtained from a large DNA library via in vitro selection) and DNA molecules are highly selective for a number of metal ions. Therefore, aptamer-based biosensors have been extensively studied for Pb2+ ion detection with a high sensitivity. In this review, we explain the current progress of Pb2+ aptamer-based sensors mainly in three groups: fluorescent; colorimetric; and electrochemical biosensors.

Aptamer-based biosensors for detection of lead(II) ion: a review

Environmental pollution, a major problem worldwide, poses considerable threat to human health and ecological environment Efficient and reliable detection technologies, which focus on the appearance of emerging environmental and trace pollutants, are urgently needed Surface-enhanced Raman scattering (SERS) has become an attractive analytical tool for sensing trace targets in environmental field because of its inherent molecular fingerprint specificity and high sensitivity In this review, we focused on the recent developments in the integration of magnetic nanoparticles (MNPs) with SERS for facilitating sensitive detection of environmental pollutants An overview and classification of different types of MNPs for SERS detection were initially provided, enabling us to categorize the huge amount of literature that was available in the interdisciplinary research field of MNPs based SERS technology Then, the basic working principles and applications of MNPs in SERS detection were presented Subsequently, the detection technologies integrating MNPs with SERS that eventually were used for the detection of various environmental pollutions were reviewed Finally, the advantages of MNP-basedSERS detection technology for environmental pollutants were concluded, and the current challenges and future outlook of this technology in practical applications were highlighted The application of the MNPs-basedSERS techniques for environmental analysis will be significantly advanced with the great progresses of the nanotechnologies, optics, and materials

Applications of magnetic nanoparticles in surface-enhanced Raman scattering (SERS) detection of environmental pollutants.

Surface water is extremely susceptible to pollution stemming from human activities, such as the expansion of urban and suburban areas, industries, cities, and agriculture. In fact, sources of surface water have become the most common discharge sites for wastewater, which may contain microorganisms, pharmaceutical waste, heavy metals, and harmful pollutants. As a reference standard for clean water, the water quality standards and index of Malaysia were used. In comparison with conventional wastewater treatment methods, new nanomaterial-based methods for water filtration and purification are drawing attention as more efficient methods for water pollution detection and treatment. This prompts the use of nanotechnology applications to control surface water pollution and quality, as surface water is the main source of water consumption for humans, animals, and plants. This paper reviewed the application of nanotechnology for the detection and treatment of surface water pollution to ensure the sustainability of a green environment. This paper also highlighted the application of nanotechnology, namely, nanofiltration membranes, photocatalysis, plasma discharge, and nano-adsorbents, in wastewater treatment, as well as the application of nano-sensors for monitoring surface water quality. The integration of nano-adsorbents in the conventional technology may increase treatment efficiency because nano-adsorbents have demonstrated remarkable performance in the removal of contaminants in wastewater. The hurdles, challenges, and outlook of nanotechnology for wastewater treatment were addressed in this review. The insights presented in this paper may provide opportunities and directions to expand studies pertaining to the applications of nanotechnology for future surface water treatment.

A review of nanotechnological applications to detect and control surface water pollution

Heavy metals accumulating in the human body produce physiological toxicity by interfering with the transport of human proteins and enzymes. Heavy metals detection is significant for food safety ass...

Detection of Heavy Metals in Food and Agricultural Products by Surface-enhanced Raman Spectroscopy

Currently, owing to the single-molecule-level sensitivity and highly informative spectroscopic characteristics, surface-enhanced Raman scattering (SERS) is regarded as the most direct and effective detection technique. However, SERS still faces several challenges in its practical applications, such as the complex matrix interferences, and low sensitivity to the molecules of intrinsic small cross-sections or weak affinity to the surface of metals. Here, we show an enrichment-typed sensing strategy with both excellent selectivity and ultrahigh detection sensitivity based on a powerful porous composite material, called mesoporous nanosponge. The nanosponge consists of porous β-cyclodextrin polymers immobilized with magnetic NPs, demonstrating remarkable capability of effective and fast removal of organic micropollutants, e.g., ~90% removal efficiency within ~1 min, and an enrichment factor up to ~103. By means of this current enrichment strategy, the limit of detection for typical organic pollutants can be significantly improved by 2~3 orders of magnitude. Consequently, the current enrichment strategy is proved to be applicable in a variety of fields for portable and fast detection, such as Raman and fluorescent sensing. The authors demonstrate a sensing approach for effectively monitoring organic micropollutants in water. They first use mesoporous nanosponge and magnetic nanoparticles for fast enrichment of micropollutants, and demonstrate SERS-based sensing with 2-3 orders of magnitude improvement in detection limits.

Ultra-rapid and highly efficient enrichment of organic pollutants via magnetic mesoporous nanosponge for ultrasensitive nanosensors

The activation of ferroptosis is a new effective way to treat drug-resistant solid tumors. Ferroptosis is an iron-mediated form of cell death caused by the accumulation of lipid peroxides. The intracellular imbalance between oxidant and antioxidant due to the abnormal expression of multiple redox active enzymes will promote the produce of reactive oxygen species (ROS). So far, a few pathways and regulators have been discovered to regulate ferroptosis. In particular, the cystine/glutamate antiporter (System Xc −), glutathione peroxidase 4 (GPX4) and glutathione (GSH) (System Xc −/GSH/GPX4 axis) plays a key role in preventing lipid peroxidation-mediated ferroptosis, because of which could be inhibited by blocking System Xc −/GSH/GPX4 axis. This review aims to present the current understanding of the mechanism of ferroptosis based on the System Xc −/GSH/GPX4 axis in the treatment of drug-resistant solid tumors.

System Xc −/GSH/GPX4 axis: An important antioxidant system for the ferroptosis in drug-resistant solid tumor therapy

Alzheimer’s disease (AD), the most common type of senile dementia, includes the complex pathogenesis of abnormal deposition of amyloid beta-protein (Aβ), phosphorylated tau (p-tau) and neuroimmune inflammatory. The neurodegenerative process of AD triggers microglial activation, and the overactivation of microglia produces a large number of neuroimmune inflammatory factors. Microglia dysfunction can lead to disturbances in iron metabolism and enhance iron-induced neuronal degeneration in AD, while elevated iron levels in brain areas affect microglia phenotype and function. In this manuscript, we firstly discuss the role of microglia in AD and then introduce the role of microglia in the immune-inflammatory pathology of AD. Their role in AD iron homeostasis is emphasized. Recent studies on microglia and ferroptosis in AD are also reviewed. It will help readers better understand the role of microglia in iron metabolism in AD, and provides a basis for better regulation of iron metabolism disorders in AD and the discovery of new potential therapeutic targets for AD.

/pdf/the-role-of-microglia-in-alzheimers-disease-from-the-2uxh43js.pdf

The Role of Microglia in Alzheimer’s Disease From the Perspective of Immune Inflammation and Iron Metabolism

Precisely probing mercury ions (Hg2+) is of essential importance to human health and environmental protection. Although numerous methods have been developed to detect Hg2+ in water, challenges still remain for rapid, accurate, and reliable detection of Hg2+ at the ppt level. In this study, a novel label-free Fe3O4@Ag based surface-enhanced Raman resonance scattering (SERRS) nanosensor has been developed for ultrasensitive and highly selective detection of Hg2+. The detection mechanism is on the basis of competitive binding interaction of Hg2+ and malachite green (MG) with nano-sliver on Fe3O4@Ag magnetic beads (MBs). In the absence of Hg2+, the Raman signal intensity of MG is significantly enhanced by the nano-silver when MG adsorbs on the nano-silver surface via one nitrogen atom. In the presence of Hg2+, the redox reaction occurring between zero-valent nano-silver and Hg2+ leads to the formation of a Ag/Hg amalgam at the Fe3O4@Ag surface, which prevents the adsorption of MG on the nano-silver surface. Thereby, the SERRS signal intensity of MG proportionally decreased with increasing Hg2+ concentration. Under optimized conditions, the proposed label-free nanosensor showed unprecedented Hg2+ detection sensitivity of 10 pM (2 ppt) with excellent selectivity. This simple sensor system can be directly applied for an inexpensive and easy-to-use monitoring method of Hg2+ in drinking water and wastewater treatment effluents that contains complicated organic and inorganic interferents.

A label-free SERRS-based nanosensor for ultrasensitive detection of mercury ions in drinking water and wastewater effluent

Malignant tumor is a major killer that seriously endangers human health. At present, the methods of treating tumors include surgical resection, chemotherapy, radiotherapy and immunotherapy. However, the survival rate of patients is still very low due to the complicated mechanism of tumor occurrence and development and high recurrence rate. Individualized treatment will be the main direction of tumor treatment in the future. Because only by understanding the molecular mechanism of tumor development and differentially expressed genes can we carry out accurate treatment and improve the therapeutic effect. MicroRNA (miRNA) is a kind of small non coding RNA, which regulates gene expression at mRNA level and plays a key role in tumor regulation. Ferroptosis is a kind of programmed death caused by iron dependent lipid peroxidation, which is different from apoptosis, necrosis and other cell death modes. Now it has been found that ferroptosis plays an important role in the occurrence and development of tumors and drug resistance. More and more studies have found that miRNAs can regulate tumor development and drug resistance through ferroptosis. Therefore, in this review, the mechanism of ferroptosis is briefly outlined, and the relationship between miRNAs and ferroptosis in tumors is reviewed.

https://www.frontiersin.org/articles/10.3389/fphar.2022.977062/pdf

Relationship between miRNA and ferroptosis in tumors

Alzheimerʼs disease (AD), an age‐related neurodegenerative disease, is a striking global health problem. Ferroptosis is a newly discovered form of cell death characterized by iron‐dependent lipid peroxidation products and the accumulation of lethal reactive oxygen species. Strict regulation of iron metabolism is essential to ensure neuronal homeostasis. Excess and deficiency of iron are both associated with neurodegeneration. Studies have shown that oxidative stress caused by cerebral iron metabolism disorders in the body is involved in the process of AD, ferroptosis may play an important role in the pathogenesis of AD, and regulating ferroptosis is expected to be a new direction for the treatment of AD. Various organelles are closely related to ferroptosis: mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosome are involved in the regulation of ferroptosis from the aspects of iron metabolism and redox imbalance. In this review, the relationship between AD and the dysfunction of organelles (including mitochondria, endoplasmic reticulum, lysosome, and Golgi apparatus) and the role of organelles in ferroptosis of AD were reviewed to provide insights for understanding the relationship between organelles and ferroptosis in AD and the treatment of AD.

Hui Long

Papers

System Xc −/GSH/GPX4 axis: An important antioxidant system for the ferroptosis in drug-resistant solid tumor therapy

The Role of Microglia in Alzheimer’s Disease From the Perspective of Immune Inflammation and Iron Metabolism

A label-free SERRS-based nanosensor for ultrasensitive detection of mercury ions in drinking water and wastewater effluent

Relationship between miRNA and ferroptosis in tumors

The key roles of organelles and ferroptosis in Alzheimerʼs disease