Search

Incorporating starch, which is a potential biodegradable substitute for petroleum-based polymers, into conventional polymers is challenging owing to limitations in processability and weak-performing resulting materials. Herein, corn starch/polyvinyl alcohol (PVA) blend films (starch: PVA ratio of 50:50) were prepared via the solvent casting method using glycerol as a plasticizer and with varying concentrations of maleic acid as the crosslinking agent. Fourier transform infrared spectroscopy revealed the molecular interactions of the maleic acid crosslinker with the polymeric network of starch and PVA through an ester linkage. The properties of the films were strongly dependent on the maleic acid concentration. An increasing maleic acid concentration imparted hydrophobicity to the film; therefore, water swelling was significantly reduced, and water resistance was enhanced. The film containing 20 wt% maleic acid exhibited excellent barrier properties, with the lowest oxygen and water vapor transmission rates of 0.5 ± 0.2 cc/m 2 ⋅day and 232.3 ± 5.4 g/m 2 ⋅day, respectively. Moreover, the mechanical properties of the film improved with increasing crosslinking. This study demonstrates that the addition of maleic acid leads to an improvement in the overall performance of starch/PVA blend films. Therefore, maleic acid-crosslinked films can be used as barrier materials in food packaging applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Nanotechnology has advanced significantly in recent years and is currently used in a wide range of sectors. Only a handful of the many diverse issues covered by nanotechnology include nanoscale gadgets, nanomaterials, nanoparticles, and nanomedicines. Its performance in treating a range of grave conditions, such as cancer, early detection of infections, analysis, bio-imaging, and bio sensing, suggests that it is highly advanced. Nanoscale materials have been employed for medicine delivery, pharmaceutics, and a range of diagnostic techniques due to their various biochemical and physical features. The use of nanoparticles that are based on nanotechnology can significantly improve the drug delivery mechanism. It is believed that nanoparticles capacity to improve the stability and solubility of drugs and shield them from impulsive inactivation during drug transfer makes it possible for them to capture, encapsulate, or bond with the molecules. The use of nanomedicine or nanoparticle-based tactics to combat viruses has emerged as a potentially life-saving tactic. These approaches have the power to protect both humans and animals against viruses. In order to inactivate a virus, nanoparticles have the unique capacity to connect with the virus epitope. Many nanocarriers have the potential to replace current drug delivery methods with focused drug delivery. Small dosages, low toxicity, and targeted flow of drug release at the infected location are all characteristics of nanocarriers or nanomedicine. Due to their distinct physicochemical and biological features, nanomaterial-based drug delivery systems (NBDDS) are frequently employed to enhance the safety and therapeutic efficacy of encapsulated pharmaceuticals. The program's objective can be supported by the applications that have so far been developed. This idea is therefore essential and sophisticated for the development of civilization. Our research will therefore concentrate on how human use of nanomedicines has changed through time in many domains., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Here, we report functionalized graphene quantum dots (GQDs) for the optical detection of arsenic at room temperature. GQDs with the fluorescence of three fundamental colors (red, green, and blue) were synthesized and functionally capped with L-cysteine (L-cys) to impart selectively towards As (III) by exploiting the affinity of L-cys towards arsenite. The optical characterization of GQDs was carried out using UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy, and fluorescence spectrometry, and the structural characterizations were performed using transmission electron microscopy. The fluorescence results showed instantaneous quenching in intensity when the GQDs came in contact with As (III) for all test concentrations over a range from 0.025 to 25 ppb, which covers the permissible limit of arsenic in drinking water. The experimental results suggested excellent sensitivity and selectivity towards As (III)., (© 2021 IOP Publishing Ltd.)

We report the solvothermal synthesis of MoS 2 based quantum dots (QDs) and the performance evaluation of bare QDs for the detection of aqueous As (III) oxidative state at room temperature and neutral pH over a vast range (0.1-1000 ppb). Concentration-dependent photoluminescence (PL) of the QDs enhances up to 50 ppb and then suppresses till 1000 ppb. It shows two distinctive slopes for enhancement and suppression. The enhancement is possibly due to the passivation of trap states or defects. The formation of tiny glassy As 2 S 3 particles on the QD surface may be the possible reason for suppression. The pattern of optical absorption of QDs follows the similar patterns of PL. Still, it shows an enhanced absorbance in the near UV range below ≤300 nm, which increases with As (III) concentration up to 50 ppb and then decreases following the PL pattern. The MoS 2 QDs were characterized by using transmission electron microscopy, x-ray diffraction, UV-Vis, and PL spectroscopy. The enhancement and suppression results were excellently fitted with the modified Stern-Volmer equation. The detection of arsenic is possible using these linear fit equations as calibration curves., (© 2021 IOP Publishing Ltd.)