Present and past anthropogenic pollution of the hydrosphere and lithosphere is a growing concern around the world for sustainable development and human health. Current industrial activity, abandoned contaminated plants and mining sites, and even everyday life is a pollution source for our environment. There is therefore a crucial need to clean industrial and municipal effluents and remediate contaminated soil and groundwater. Nanosized zero-valent iron (nZVI) is an emerging material in these fields due to its high reactivity and expected low impact on the environment due to iron’s high abundance in the earth crust. Currently, there is an intensive research to test the effectiveness of nZVI in contaminant removal processes from water and soil and to modify properties of this material in order to fulfill specific application requirements. The number of laboratory tests, field applications, and investigations for the environmental impact are strongly increasing. The aim of the present review is to provide an overview of the current knowledge about the catalytic activity, reactivity and efficiency of nZVI in removing toxic organic and inorganic materials from water, wastewater, and soil and groundwater, as well as its toxic effect for microorganisms and plants.

The early diagnosis of diseases, e.g., Parkinson’s and Alzheimer’s disease, diabetes, and various types of cancer, and monitoring the response of patients to the therapy plays a critical role in clinical treatment; therefore, there is an intensive research for the determination of many clinical analytes. In order to achieve point-of-care sensing in clinical practice, sensitive, selective, cost-effective, simple, reliable, and rapid analytical methods are required. Biosensors have become essential tools in biomarker sensing, in which electrode material and architecture play critical roles in achieving sensitive and stable detection. Carbon nanomaterials in the form of particle/dots, tube/wires, and sheets have recently become indispensable elements of biosensor platforms due to their excellent mechanical, electronic, and optical properties. This review summarizes developments in this lucrative field by presenting major biosensor types and variability of sensor platforms in biomedical applications.

Novel carbon microsphere-supported metallic copper nanoparticles (Cu-NP/C) were synthesized using a low-cost and facile method based on carbonising a styrene-based, chelate-forming cation exchange resin loaded with Cu²⁺ ions. The metal–organic framework served as both copper and carbon source. Cu-NP/C microspheres were characterized by XRD, Raman, SEM, TGA, EDAX, and BET surface area analyser and were employed as heterogeneous catalysts for the reduction of 4-nitrophenol to 4-aminophenol by NaBH₄ and for the synthesis of medicinally significant hexahydroquinoline derivatives based on the one-pot, multi-component reaction of aldehydes, dimedone, ethyl acetoacetate, and ammonium acetate. The sustainable and cheap starting material, the relatively easy synthetic procedure, the catalytic efficiency, and the easy separation and reusability of Cu-NP/C microspheres open the door for their wide-scale application.