Energy‐efficient, high‐specificity gas sensors provide practical suitability for stability and response factors. The recognition of ignitable gases (methane (CH₄), propane (C₃H₈), and hydrogen (H₂) and harmful gases (carbon oxide (CO) and hydrogen sulfide (H₂S)) in an enclosed and out‐of‐door space are essential to safeguard the human lives and infrastructural spaces. One of the crucial conductive‐type metal oxide semiconductor (MOS) gas sensors yielding wide applications is zinc oxide (ZnO). This study highlights the various types of ZnO gas sensors, their fabrication techniques, and specific vital characterizations. The devices based on MOS are utilized to sense various target gases through redox reactions. The variation in oxide surface with target gas interactions is transduced to a change of sensor conductance. This review also provides insight into integrating ZnO gas sensors with technologies such as materials engineering, the Internet of things and big data. Moreover, this review addresses ZnO gas sensors’ challenges and future directions.

The integration of nanotechnology in agriculture offers a transformative approach to improving crop yields, resource efficiency, and ecological sustainability. This review highlights the application of functional NM, such as nano-formulated agrochemicals, nanosensors, and slow-release fertilizers, which enhance the effectiveness of fertilizers and pesticides while minimizing environmental impacts. By leveraging the unique properties of NM, agricultural practices can achieve better nutrient absorption, reduced chemical runoff, and improved water conservation. Innovations like nano-priming can enhance seed germination and drought resilience, while nanosensors enable precise monitoring of soil and crop health. Despite the promising commercial potential, significant challenges persist regarding the safety, ecological impact, and regulatory frameworks for nanomaterial use. This review emphasizes the need for comprehensive safety assessments and standardized risk evaluation protocols to ensure the responsible implementation of nanotechnology in agriculture.

This study examines the ab initio emulsion atom transfer radical polymerization (ATRP) initiated by an eco-friendly reducing agent to produce poly(methyl methacrylate) (PMMA) polymer with controlled characteristics in a 2 L stirred batch reactor. The effect of the reaction temperature, surfactant concentration, monomer to water ratio, and stirring speed was thoroughly investigated. The results showed that PMMA coagulation becomes quite severe at a certain temperature threshold. However, the coagulation could be avoided at mild reaction temperature, since the outcomes showed that loading more surfactant to the system under high mixing speed has balanced the polymer mixture and yielded high monomer conversion. The PMMA product was analyzed by gravimetry and GPC measurements and after 5 h of polymerization at a reaction temperature of 50 °C, monomer conversion of 64.1% was obtained, and PMMA polymer samples produced had an average molar mass of 4.5 kg/mol and a polydispersity index of 1.17. The structure of the PMMA polymer was successfully proved by FTIR and nuclear magnetic resonance (NMR) spectroscopy. The results confirm the living feature of MMA AGET ATRP in emulsion medium and recommend further investigation for other types of surfactant.