The development of sustainable energy technologies has received considerable attention to meet increasing global energy demands and to realise organisational goals (e.g., United Nations, the Paris Agreement) of carbon neutrality.

Heavy and transition metal (HTM) ions have significant harmful effects on the physical environment and play crucial roles in biological systems; hence, it is crucial to accurately identify and quantify any trace pollution. Molecular sensors which are based on organic molecules employed as optical probes play a crucial role in sensing and detecting toxic metal ions in water, food, air, and biological environments. When appropriate combinations of conduction and selective recognition are combined, fluorescent and colorimetric chemosensors are appealing instruments that enable the selective, sensitive, affordable, portable, and real-time investigation of the possible presence of heavy and transition metal ions. This feature article aims to provide readers with a more thorough understanding of the different methods of synthesis and how they work. As noted in the literature, we will highlight colorimetric and fluorometric sensors based on their receptors into multiple categories for heavy metal ion detection, such as Hg²⁺, Ag²⁺, Cd^2+, Pb²⁺, and In³⁺, and simultaneous multiple-ion detection.

The development of optical chemosensors for the sensitive and selective detection of trace-level metal ions in aqueous solutions has drawn a lot of attention from the scientific community in recent years. Organic sensors offer a number of advantages over traditional identification techniques, including low cost, high sensitivity, selectivity, and simplicity of synthesis. We will focus on colorimetric and fluorometric sensors based on their receptors for the real-time detection of certain first-row transition metal ions like Cr³⁺, Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺ Cu²⁺, and Zn²⁺. The development of these sensors will aid in the rapid and simple resolution of several problems linked to the detection of potentially hazardous metal ions at trace levels in diverse biological and environmental components. This review article not only gives a comprehensive understanding of the existing techniques, but also encourages more research efforts to address the evolving demands in the field of trace transition metal ion detection.

The profound pharmacological attributes of macrocyclic compounds have spurred their transformation into pharmaceutical drugs. Within conformationally pre-organized ring structures, the macrocycle’s intricate functions and stereochemical complexity contribute to a heightened affinity and selectivity for protein targets. Simultaneously, they maintain sufficient bioavailability to penetrate intracellular locations. As a result, the construction of macrocycles emerges as an optimal strategy for addressing the challenge of “undruggable” targets like cancer. Cancer stands as the second most prevalent and formidable threat to human life, prompting researchers to channel their efforts toward the extraction and synthesis of effective therapeutic drugs designed on macrocyles to combat various types of cancer cells. Many macrocyclic drugs have been licensed by the Food and Drug Administration (FDA) for the treatment of cancer patients. Nonetheless, the significance of these compounds in the production of cancer therapeutics is still undervalued. According to recent research, macrocyclic compounds can be a useful tactic in the fight against drug resistance in the treatment of cancer. This chapter aims to present bits of evidence about the uses of macrocyclic compounds as potential cancer treatments. By providing more innovative approaches to aid cancer patients and society as a whole, this chapter will hopefully stimulate greater interest in the development of macrocyclic medicines for cancer therapy.

Adsorption and detection of chlorofluorocarbons (CFCs) using 2D materials are environmentally important because of their toxicity and persistence. This study investigates a graphenylene nanosheet for CFC sensing.