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Environmental monitoring of pesticide residues has become increasingly crucial for ensuring food safety and environmental sustainability. Current demands are not met by traditional analytical tools, but the integration of smartphones, due to their small size, high accessibility, fast processing speed, and powerful imaging capacity, holds significant potential for on-site detection of pesticide residues. This review provides a comprehensive overview of the latest developments in the application of molecularly imprinted polymer (MIP) sensors equipped with smartphones for the detection of pesticide residues in environmental samples, covering the period from 2018 to 2024. The review encompasses recent advancements in MIP synthesis, sensor fabrication, and the incorporation of principles for improved signal precision with the integration of smartphones based on sensing signals (optical and electrochemical signals). Additionally, the diverse range of environmental samples were explored, including water, soil, and crops, where MIP sensors have demonstrated their efficacy in detecting pesticides. The potential for real-time monitoring and the challenges associated with deploying these sensors at lab scale are discussed. Overall, this review highlights the transformative impact of MIP sensors with smartphone-based detection in the field of pesticide residue analysis, paving the way for enhanced environmental monitoring practices.

The field of propellants has recently witnessed dynamic shift, including advancements in propulsion technology and a growing emphasis on the development of environmentally friendly propellants. Nitrate ester (NE) are extensively used in solid propellants, exhibiting chemical instability as they undergo decomposition reactions. Stabilization is a crucial aspect in propellant, ensuring the safety and reliable performance of energetic materials. Stabilizer plays a vital role in inhibiting or slowing down the autocatalytic decomposition reaction of propellants. In response to grow health and environmental concerns, there is a continuous effort to explore and evaluate green stabilizers designed to replace traditional stabilizers, which have been associated with adverse environmental impacts. Therefore, this study aimed to provide an overview of the current research carried out in the field of NE-based propellants, emphasizing the most significant work undertaken on green stabilizer materials for NE-based propellants. A comprehensive review of various environmentally friendly and low-toxicity stabilizers employed in propellants are presented, and their effects on the stability and shelf-life performance of NE-based propellants are discussed. Furthermore, this paper delves into the stabilization mechanisms of green stabilizers to mitigate decomposition reactions, thereby preventing unwanted side effects and ensuring long-term storage stability. Through a comprehensive review of recent developments, the manuscript highlights the successes and challenges associated with the incorporation of green stabilizers in NE-based propellants formulations. Finally, the review concludes by outlining future research directions and opportunities for innovation in sustainable and green stabilizers as well as key issues that need to be addressed and resolved. The comprehensive review and insights provided in this study contribute to the ongoing efforts in developing safer and more sustainable propellant technologies.

Stabilizers play a crucial role in preventing undesirable decomposition and degradation reactions of propellants, thus ensuring their long-term performance and safe storage. This review highlights recent advancements in stabilizer selection and formulation techniques, aiming to enhance the stability of single base nitrocellulose (SB-NC) propellants. It examines several types of stabilizers for SB-NC propellants, including their reaction mechanisms and effectiveness in preventing degradation reactions of the propellants, as well as the effects of their concentrations, particle sizes, and distributions on the propellants’ stability. Furthermore, it explores innovative approaches such as nano and green stabilizers with improved stability and compatibility. This review also provides insights into methods for evaluating the efficiency and propellant stability of the stabilizers, such as thermal analysis and accelerated aging tests. The findings of this review will assist in developing advanced propellant formulations that meet the growing demand for the applications of NC-based propellants.

The incorporation of intermittent renewable energy sources into a consistently controlled power transmission system hinges on advancements in energy storage technologies. Sodium ion batteries (SIBs) are emerging as a primary and viable alternative material due to their electrochemical activity, presenting a potential replacement for the next generation of lithium-ion battery (LIB) energy storage materials. However, this transition may necessitate significant alterations in the anode material, given the incompatibility of the current anode with sodium ions and the electrolyte. This review provides a comprehensive summary of various anode materials employed in SIBs, categorized according to their storage mechanisms. Additionally, it explores the growing focus on utilizing hard carbon as an anode material, driven by factors such as its relatively high specific capacity compared to graphite, cost-effective production, and eco-friendly properties as it can be derived from biomass. The review further addresses recent progress in hard carbon, detailing production methods, modifications, challenges, limitations in integrating hard carbon into the anode of SIBs, and suggests potential directions for future research.

Newly synthesized benzoyl kappa carrageenan (Bz-ƙcar) was successfully produced by the Friedel Craft acylation method. The successful substitution of benzoyl molecule into kappa carrageenan (ƙcar) polymeric chain was confirmed by the FTIR analysis based on the formation of new carbonyl (CO) and CC bonds in Bz-ƙcar. 1H NMR analysis further proved the benzoylation by the appearance of new multiple resonances peaks at δ = 6.6–9.50 ppm, which belonged to the characteristic signals of protons in the aromatic benzoate group. XRD analysis showed reduced crystallinity of the synthesised carrageenan, while elemental analyser analysis revealed the increased percentages of carbon in Bz-ƙcar upon the substitution. The highest degree of substitution obtained was 0.27. TGA showed lower degradation temperature in the synthesised carrageenan, while water contact angle analysis demonstrated that Bz-ƙcar was less hydrophilic as compared to the pristine ƙcar. Solubility tests showed that Bz-ƙcar was best dissolved in ethylene glycol. The benzoylation also improved the ionic conductivity of Bz-ƙcar to 3.10 × 10−4 Scm−1 at ambient temperature.

Gel polymer electrolytes (GPEs) are regarded as a prospective alternative for traditional liquid electrolytes. The dispersion of nanofiller in GPEs has been proven to improve the electrolyte’s properties, such as reduced reactivity and leakage, improved safety, better shape flexibility, as well as manufacturing integrity. Meanwhile, the introduction of Electron Beam (EB) radiation remarkably enhances the electrochemical properties of GPEs. Therefore, the aim of the present work was to investigate the properties of titania-filled 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4)–poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) upon in-situ surface modification using vinyltriethoxysilane (VTES) coupling agent and its response towards 8 MeV energy EB irradiation. Following the surface modification of titania using VTES at different weight percentages (10–40%) and EB radiation exposure (5–20 kGy), the physicochemical, thermal, morphological, and electrochemical characteristics of the GPE were analyzed via Fourier Transform Infrared spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM), and impedance analysis, respectively. Based on the results, the TGA analysis showed that the thermal stability of the GPE increased with the increment of residues, which indicate the successful ceramics attachment onto the silanol group from the silane in the VTES compound. After the surface modification on the ceramic particle, the obtained average size particle was 50 nm with further enhancement of the particle distribution was observed when exposed to EB radiation. Additionally, the impedance analysis showed that the modified surface of the titania system achieved an optimum ionic conductivity of 10−2 S cm−1 at room temperature. When the electrolytes were exposed to EB radiation, the ionic conductivity increased up to 10−1 S cm−1 with the lithium transference number calculated at 0.52. These remarkable findings indicate that the developed surface modification technique of titania together with EB radiation on GPEs is a promising electrolyte for lithium-ion battery application.

Enzymatic detection of organophosphate (OP) compounds can be tailored using highly sensitive and selective enzymes in the development of biosensors. Previously, mutant (YT) phosphotriesterase (PTE) was reported to efficiently hydrolyze Sp and Rp enantiomers of phosphotriester. This study reports the use of phosphotriesterase mutant YT (YT-PTE) immobilized onto reduced graphene oxide (rGO) and fabricated onto a screen-printed carbon electrode (SPCE) for electrochemical detection of OP compounds. Immobilization of YT-PTE onto rGO was secured using N-hydroxysuccinimide (NHS) and N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide (EDC) cross-linker, and the resulting immobilized enzyme was able to retain up to 90% of its activity. Electrochemical analysis of the SPCE/rGO/YT-PTE showed detection of paraoxon in a linear range of 1 mM–0.005 μM with its limit of detection as low as 0.11 μM. SPCE/rGO/YT-PTE exhibited high selectivity towards paraoxon and parathion and have good reproducibility. Furthermore, detection of paraoxon was also possible in a real water sample with only minor interferences.

Chlorine gas is extensively utilised in industries as both a disinfectant and for wastewater treatment. It has a pungent and irritating odour that is comparable with that of bleach and can cause serious health issues such as headaches and breathing difficulties. Hence, efficiently, and accurately monitoring chlorine gas is critical to ensure that no undesirable incidents occur. Due to its remarkable characteristics, numerous researchers have explored the potential of ferrite nanoparticles as a sensing material for chlorine gas detection. Among several ferrite nanoparticles, nickel ferrite (NiFe2O4) is extensively studied as an inverse spinel structured magnetic material that may be ideal for sensing applications. However, the magnetic characteristics of NiFe2O4 cause agglomeration, which necessitates the use of a substrate for stabilisation. Therefore, nanocellulose (NC), as a green and eco-friendly substrate, is ideal for stabilising bare nickel ferrite nanoparticles. In a novel experiment, nickel ferrite was loaded onto NC as a substrate using in situ deposition. The structure was confirmed by X-ray Diffraction (XRD) analysis, while elemental composition was verified by Energy dispersive X-ray (EDX) analysis. Gas sensing properties were determined by evaluating sensitivity as a function of various regulating factors, such as the amount of nickel ferrite, gas concentration, repeatability, and reusability. In the evaluation, 0.3 g nickel ferrite showed superior response and sensitivity than those of other samples. The achieved response time was around 40 s, while recovery time was about 50 s. This study demonstrates the potential of a nickel ferrite/nanocellulose-based nanocomposite to efficiently monitor chlorine gas.

Polypyrrole (PPy) has been widely used as a sensing material in many studies as PPy gives out noticeable reactions towards varieties of vapours of acids, bases, alcohols, alkanes, and chemical warfare agent (CWA) simulants. However, due to dispersion and mechanical properties limitation, PPy in nanoparticles (PPy NPs) has been introduced. The combinations between PPy NPs and nanosized metal oxide have shown promising improvement in the sensitivity of a sensor due to the larger total surface area of detection. In this study, the potential of PPy NPs and polypyrrole-iron oxyhydroxide (PFFs) nanocomposite as sensing materials in detecting the CWA simulant, dimethyl methylphosphonate (DMMP), is investigated. PPy NPs and modified PFFs nanocomposite were successfully synthesised using chemical oxidative polymerisation. The formation of PPy NPs and the effect of iron-oxyhydroxide (FeOOH) on the chemical interaction, morphology, and size of PPy NPs were investigated using attenuated total reflection-Fourier transform infrared (ATR-FTIR), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). ATR-FTIR analysis showed that the modified PFFs nanocomposite was successfully produced through the presence of a sharp –OH peak. The size of the prepared PPy NPs and PFFs nanocomposite was observed in the range of 50 to 70 nm and 110 to 160 nm, respectively, through TEM analysis. The electrochemical behaviour of PPy NPs and PFFs nanocomposite towards DMMP was investigated using cyclic voltammetry (CV) where, in the presence of DMMP, PPy NPs and PFFs nanocomposite showed 24% and 21% current signal reduction, respectively. This suggests that both PPy NPs and PFFs nanocomposite are able to discriminate an electrical signal both with and without the presence of DMMP.

Acephate (Ac), an organophosphate (OP) insecticide, is very harmful to human and the environment. Conventional techniques of detection are sensitive and selective but relatively time-consuming, expensive, and require trained personnel. This paper describes the use of an image processing technique to digitize the red values (RVs) of the colour image of Ac-capped gold nanoparticles (Ac-Cit-AuNPs) complex captured using a digital microscope to improve the detection accuracy and precision. The formation of the suspension was characterised using laser test, ultraviolet-visible spectrophotometer (UV-Vis), high-resolution transmission electron microscope (HRTEM), and Fourier Transform infrared spectroscope (FTIR). The linear regression analysis revealed that the detection sensitivity improved as the smaller gold nanoparticles were used. For quantitative measurement using image processing, a good linear relationship (R2 = 0.9905 and 0.9924) for Cit-HAuNPs and Cit-MAuNPs, respectively, between the concentration of Ac and average red values was obtained in the range of 0–8 mM. The limit of detection (LOD) for Ac was found to be 0.3 mM and 0.4 mM for Cit-MAuNPs and Cit-HAuNPs, respectively.

The wide availability and diversity of dangerous microbes poses a considerable problem for health professionals and in the development of new healthcare products. Numerous studies have been conducted to develop membrane filters that have antibacterial properties to solve this problem. Without proper protective filter equipment, healthcare providers, essential workers, and the general public are exposed to the risk of infection. A combination of nanotechnology and biosorption is expected to offer a new and greener approach to improve the usefulness of polysaccharides as an advanced membrane filtration material. Nanocellulose is among the emerging materials of this century and several studies have proven its use in filtering microbes. Its high specific surface area enables the adsorption of various microbial species, and its innate porosity can separate various molecules and retain microbial objects. Besides this, the presence of an abundant OH groups in nanocellulose grants its unique surface modification, which can increase its filtration efficiency through the formation of affinity interactions toward microbes. In this review, an update of the most relevant uses of nanocellulose as a new class of membrane filters against microbes is outlined. Key advancements in surface modifications of nanocellulose to enhance its rejection mechanism are also critically discussed. To the best of our knowledge, this is the first review focusing on the development of nanocellulose as a membrane filter against microbes.

Conducting polymers have been widely used in electrochemical sensors as receptors of the sensing signal’s analytes and transducers. Polypyrrole (PPy) conducting polymers are highlighted due to their good electrical conductive properties, ease in preparation, and flexibility of surface characteristics. The objective of this review paper is to discuss the theoretical background of the two main types of electrochemical detection: impedimetric and voltammetric analysis. It also reviews the application and results obtained from these two electrochemical detections when utilizing PPy as a based sensing material in electrochemical sensor. Finally, related aspects in electrochemical sensor construction using PPy will also be discussed. It is anticipated that this review will provide researchers, especially those without an electrochemical analysis background, with an easy-to-understand summary of the concepts and technologies used in electrochemical sensor research, particularly those interested in utilizing PPy as a based sensing material.