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Nitrous oxide (N 2 O), also known as laughing gas, is arguably one of the most detrimental greenhouse gases while concurrently being overlooked by the public. Specifically, N 2 O is ∼300 times more damaging than its better-known counterpart carbon dioxide (CO 2 ) and has a longer-lived lifetime in the atmosphere than CO 2 . There exist both natural and anthropogenic sources of N 2 O, and thus, for a better understanding of sources, capture, and decomposition, it is pivotal to identify N 2 O within the nitrogen biosphere. This review covers the past and current low-cost N 2 O gas-sensing technologies, focusing specifically on low-cost metal oxide semiconductors (MOSs), chemiresistive and electrochemical sensors that can provide spatial and temporal monitoring of N 2 O emissions from various sources. Additionally, compositional modifications to MOsS using metal− organic frameworks (MOFs) are discussed, potentially facilitating new awareness and efforts for increased sensing performance and functionality in N 2 O detection.

The drawbacks of conventional drug administration include repeated administration, non-specific biodistribution in the body’s systems, the long-term unsustainability of drug molecules, and high global cytotoxicity, posing a challenge for the efficient treatment of chronic diseases that require varying drug dosages over time for optimal therapeutic efficacy. Most controlled-release methods encapsulate drug molecules in biodegradable materials that dissolve over time to release the drug, making it difficult to deliver drugs on a schedule. To address these limitations, we developed a magneto-, opto-stimuli responsive drug delivery system based on functionalized electrospun nanofibers loaded with superparamagnetic iron oxide nanoparticles (SPIONs). We exploited the Néel relaxation effect of SPIONs, where heat generated from vibrating SPIONs under exogenously applied magnetic fields or laser illumination induced structural changes of the thermo-sensitive nanofibers that encapsulate the particles. We showed that this structural change of nanofibers is the governing factor in controlling the release of dye molecules, used as a model drug and co-encapsulated within the nanofibers. We also showed that the degree of nanofiber structural change depends on SPION loading and duration of stimulation, demonstrating the tunability of the drug release profile. Overall, we demonstrated the potential of SPION-embedded thermoplastic nanofibers as an attractive platform for on-demand drug delivery.

To understand the effect of complexing agents (i.e., ammonium and citrate) in nickel–molybdenum electrodeposition, calculation of the concentration of various Ni and Mo species as a function of pH and initial concentration of metal ions and complexing agents was performed. In addition, linear sweep voltammetry and Hull cell experiments were systematically investigated to understand the effect of current density and ammonium-to-citrate ratio to film compositions, morphology, and crystallinity. The results indicated that Ni(NH3)32+ played a critical role in induced co-deposition mechanism of Ni–Mo alloys, which involved the reduced Ni and absorbed H atoms. Microstructure analysis of deposits indicated that the transition from smooth laminarly grown amorphous Ni–Mo–O composites to columnar and nanocrystalline metallic Ni–Mo alloys with a globular structure as the ammonium-to-citrate molar ratio increases. The highest Mo content of alloys was as high as 19 at%, and up to 70 at% O was present in the composites.

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