Recent advances in analytical, bioanalytical and miscellaneous applications of green nanomaterial

Synthesis of imidazolium ionic liquid immobilized on magnetic mesoporous silica: A sorbent material in a green micro-solid phase extraction of multiclass pesticides in water

In this study, we synthesized an imidazolium ionic liquid immobilized on magnetic mesoporous silica (IL-MMS) and evaluated its performance as a sorbent material for a green micro-solid phase extraction (μ-SPE) of multiclass pesticides in water. The synthesized IL-MMS was characterized by various analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses (N2 adsorption/desorption), Vibrating Sample Magnetometer (VSM), energy-dispersive spectroscopy (EDS) and Field emission scanning electron microscopy (FESEM). Our synthesized IL-MMS demonstrated excellent magnetic properties (31.5 emu/g), high surface area (1177.4 m2/g), proper pore size (⁓4.2 nm) and volume (1.80 cm3/g). Under optimized extraction conditions, the IL-MMS exhibited a high adsorption capacity for a variety of pesticides, including organophosphates, carbamates, and pyrethroids. The proposed μ-SPE method using IL-MMS showed good linearity (R2 > 0.99), low limits of detection (LODs) ranging from 0.04 to 1.63 ng/L, and suitable recovery rate was between 82.4% and 109.8% for different pesticides. In addition, the method also exhibited excellent reproducibility, with relative standard deviations (RSDs) of less than 8% for both intra and inter-day precision. In overall, the synthesized IL-MMS has proven to be a highly promising material for sorbent-based micro-solid phase extraction (μ-SPE) of multiclass pesticides in water. With its simple, efficient, and eco-friendly approach to pesticide analysis, this method shows great potential for future pesticide detection and monitoring efforts due to its sensitivity, accuracy, and adaptability to various environmental conditions.

Cellulose nanofiber-based multifunctional films integrated with carbon dots and anthocyanins from Brassica oleracea for active and intelligent food packaging applications

A new generation of carbon dot-based active and intelligent packaging films with UV blocking, antibacterial, and real-time sensing potentials was fabricated using Brassica oleracea (BO) extract. The cellulose nanofiber (CNF) was used to prepare the multifunctional intelligent nanocomposite film integrated with BO anthocyanins (BOA) and BO-biowaste-derived carbon dots (BO-CDs). The incorporation of 1.5 % BO-CD and 6 % BOA in the CNF matrix improved the physicochemical and UV blocking (>189 % increase) properties of the fabricated films. The synthesized BO-CD exhibits high fluorescence, UV absorption, antibacterial and antioxidant functions. It showed strong radical scavenging activity against ABTS (~90 %) and DPPH (~80 %) compared to the neat CNF film. Scanning electron microscopy and X-ray photoelectron spectroscopy (XPS) have shown enhanced compatibility and elemental composition of the BO-CDs/BOA additives in the CNF-polymer matrix. Packaging tests showed that the prepared film worked efficiently and non-destructively and was able to monitor the freshness of minced pork, fish, and shrimp in real-time through a distinct visual change from red to colorless/yellow during storage at 25 °C for 48 h. Active and intelligent films developed based on CNF/BO-CDs/BOA are expected to be applied as multifunctional packaging materials that can indicate quality changes and extend the shelf life of packaged perishable foods.

The versatility of nanocellulose, modification strategies, and its current progress in wastewater treatment and environmental remediation

Deterioration in the environmental ecosystems through the depletion of nonrenewable resources and the burden of deleterious contaminants is considered a global concern. To this end, great interest has been shown in the use of renewable and environmentally-friendly reactive materials dually to promote environmental sustainability and cope with harmful contaminants. Among the different available options, the use of nanocellulose (NC) as an environmentally benign and renewable natural nanomaterial is an attractive candidate for environmental remediation owing to its miraculous physicochemical characteristics. This review discusses the intrinsic properties and the structural aspects of different types of NC, including cellulose nanofibrils (CNFs), cellulose nanocrystals (CNCs), and bacterial cellulose (BC) or bacterial nanocellulose (BNC). Also, the different modification strategies involving the functionalization or hybridization of NC by using different functional and reactive materials aimed at wastewater remediation have been elaborated. The modified or hybridized NC has been explored for its applications in the removal or degradation of aquatic contaminants through adsorption, filtration, coagulation, catalysis, photocatalysis, and pollutant sensing. This review highlights the role of NC in the modified composites and describes the underlying mechanisms involved in the removal of contaminants. The life-cycle assessment (LCA) of NC is discussed to unveil the hidden risks associated with its production to the final disposal. Moreover, the contribution of NC in the promotion of waste management at different stages has been described in the form of the five-Rs strategy. In summary, this review provides rational insights to develop NC-based environmentally-friendly reactive materials for the removal and degradation of hazardous aquatic contaminants.

Ionic liquid-based magnetic nanoparticles for magnetic dispersive solid-phase extraction: A review

Due to their highly tunable nature and outstanding physicochemical properties, ionic liquids (ILs) have been widely reported for use in the synthesis of multitudinous magnetic nanoparticles (MNPs). IL-based magnetic nanoparticles (IL-MNPs) have great potential in magnetic dispersive solid-phase extraction (MDSPE). At present, IL-MNPs have been successfully applied in the pretreatment of MDSPE samples from medicines, pesticides, veterinary drugs, heavy metals, dyes, additives, and proteins in agricultural products, foods and beverages, environmental water, and biological samples. In this review, the preparation of IL-MNPs and their application in MDSPE are comprehensively summarized. The structural characteristics of the introduced ILs used to prepare the IL-MNPs and the synthetic routes employed to obtain the IL-MNPs are described, including physical coating and chemical bonding methods. The IL-MNPs are then classified and described according to different modified materials, including silica-based materials, carbon-based materials, metal-organic frameworks, molecularly imprinted polymers and other interesting large/small molecules. Finally, the research prospects and development directions of IL-MNPs in the context of MDSPE are further identified.

Recent Developments in Carbon Quantum Dots: Properties, Fabrication Techniques, and Bio-Applications

Carbon dots have gained tremendous interest attributable to their unique features. Two approaches are involved in the fabrication of quantum dots (Top-down and Bottom-up). Most of the synthesis methods are usually multistep, required harsh conditions, and costly carbon sources that may have a toxic effect, therefore green synthesis is more preferable. Herein, the current review presents the green synthesis of carbon quantum dots (CQDs) and graphene quantum dots (GQDs) that having a wide range of potential applications in bio-sensing, cellular imaging, and drug delivery. However, some drawbacks and limitations are still unclear. Other biomedical and biotechnological applications are also highlighted.