A review of some papers published in the last fifty years that focus on the semiconducting metal oxide (SMO) based sensors for the selective and sensitive detection of various environmental pollutants is presented.

In the last decade, gold and silver nanomaterials have received considerable attention due to their attractive electronic and chemical properties and their potential applications in the development of new technologies. Recent advances in the study of various gold and silver nanomaterials have led to their utilization in a number of very important applications including biosensing, diagnostic imaging, and cancer diagnosis and therapy. This review surveys the various synthetic methods of gold and silver nanomaterials. Recent experimental studies focusing on the use of gold and silver nanomaterials in catalysis, food industry, and environmental conservation are also reviewed. This review also highlights the advantages of gold and silver nanomaterials in the development of fluorescence biosensors, glucose biosensors, nucleic acids-based biosensors, and protein-based biosensors. Moreover, the potent in vitro and in vivo anti-microbial and cyto-genotoxic effects of various gold and silver nanomaterials are underlined. Finally, recent advances in the employment of gold and silver nanomaterials as effective drug delivery vehicles and promising cancer therapeutic agents are summarized. Despite their use in remediating numerous medical and health-related conditions, the efficacy and safety of many gold and silver nanomaterials is still under some scrutiny. Needless to say, researchers are facing many challenges and obstacles in their ample attempts to synthesize nanomaterials that are relatively easy to design, inexpensive to fabricate, and effective in treating various diseases, but at the same time display a very low, if any, toxicity to the body. Future investigations should aim at overcoming such challenges in an attempt to design nanomaterials that will prove to be useful in diagnosing and treating life-threatening diseases while ensuring a high degree of efficacy and safety.

A pyrene-based benzimidazole-linked polymer (BILP-10) has been synthesized by the co-condensation of 1,3,6,8-tetrakis(4-formylphenyl)pyrene and 1,2,4,5-benzenetetramine tetrahydrochloride in dimethylformamide. The use of pyrene as a molecular building unit leads to the formation of self-assembled nanofibers that have moderate surface area (SA_BET = 787 m² g⁻¹) and very high CO₂/N₂ (128) and CO₂/CH₄ (18) selectivities at 273 K. Furthermore, results from gas uptake measurements indicate that BILP-10 can store significant amounts of CO₂ (4.0 mmol at 273 K/1.0 bar) and H₂ (1.6 wt% at 77 K/1.0 bar) with respective isosteric heats of adsorption of 38.2 and 9.3 kJ mol⁻¹ which exceed all of the previously reported values for BILPs and are among the highest values reported to date for unmodified porous organic polymers. Under high pressure settings, BILP-10 displays moderate uptakes of H₂ (27.3 g L⁻¹, 77 K/40 bar), CH₄ (72 L L⁻¹, 298 K/40 bar), and CO₂ (13.3 mmol g⁻¹, 298 K/40 bar). The unusually high CO₂ and H₂ binding affinities of BILP-10 are presumably facilitated by the amphoteric pore walls of the polymer that contain imidazole moieties and the predominant microporous nature.

The capture and safe storage of radioactive iodine (¹²⁹I or ¹³¹I) are of a compelling significance in the generation of nuclear energy and waste storage. Because of their physiochemical properties, Porous Organic Polymers (POPs) are considered to be one of the most sought classes of materials for iodine capture and storage. Herein, we report on the preparation and characterization of two triazine-based, nitrogen-rich, porous organic polymers, NRPOP-1 (SA_BET = 519 m² g⁻¹) and NRPOP-2 (SA_BET = 456 m² g⁻¹), by reacting 1,3,5-triazine-2,4,6-triamine or 1,4-bis-(2,4-diamino-1,3,5-triazine)-benzene with thieno[2,3-b]thiophene-2,5-dicarboxaldehyde, respectively, and their use in the capture of volatile iodine. NRPOP-1 and NRPOP-2 showed a high adsorption capacity of iodine vapor with an uptake of up to 317 wt % at 80 °C and 1 bar and adequate recyclability. The NRPOPs were also capable of removing up to 87% of iodine from 300 mg L⁻¹ iodine-cyclohexane solution. Furthermore, the iodine-loaded polymers, I₂@NRPOP-1 and I₂@NRPOP-2, displayed good antibacterial activity against Micrococcus luteus (ML), Escherichia coli (EC), and Pseudomonas aeruginosa (PSA). The synergic functionality of these novel polymers makes them promising materials to the environment and public health.