Bio-inspired formulation of starch-coated silver nanoparticles: A sustainable computing towards environmental monitoring and biomedical sectors

This manuscript explores the interdisciplinary integration of quantum dot–hydrogel composites and smart materials and their applications across a spectrum of fields, including biomedical engineering, environmental sensing, and energy harvesting. It covers the synthesis of novel materials like fluorescent hydrogel nanocomposites that display enhanced chemical stability, mechanical strength, and thermal resistance, highlighting their utility in environmental monitoring and catalysis. In the biomedical sector, innovations include hydrogel composites for targeted drug delivery and advanced therapies such as photothermal DNA hydrogels for tumor treatment. This review also discusses the application of these materials in imaging, diagnostics, and the development of smart sensors capable of detecting various biological and environmental changes. Its scope further extends to optoelectronics and the design of energy-efficient systems, underscoring the versatile functionalities of hydrogels in modern technological applications. Challenges remain in scaling up these technologies for commercial use and ensuring their long-term stability and safety, necessitating future research focused on sustainable, scalable solutions that can be integrated into existing systems.

Herein, we demonstrate a novel approach for development of TiO2 grafted 2D-TiC nanosheets (TiO2@2D-TiC) based room temperature operable, flexible ethanol gas sensor. The homogeneous distribution, unique composition, and crystalline microstructure of TiO2 nanoparticles grafted 2D-TiC nanosheets have been found to enhance the surface reactivity and efficiency of its transducer–receptor functions. The electron–hole recombination at the TiO2/2D-TiC interfaces offered superior sensor performance with fast response and recovery times. Moreover, TiO2@2D-TiC nanosheets based flexible sensor exhibited high selectivity toward trace-level ethanol gas (10 ppb–60 ppm) with extremely low noise-to-signal ratio and excellent stability. The results suggest that the development of low-cost flexible sensors based on TiO2@2D-TiC nanosheets could be applied for potential applications, such as printed/wearable electronics, biomedical sector and environmental monitoring.

To investigate the effect of polyelectrolytes on the formation and physicochemical properties of chitosan nanoparticles (CS-NPs) used for the delivery of an anticancer drug, doxorubicin (DOX). Three DOX-loaded CS-NPs were formulated with tripolyphosphate (CS-TP/DOX NPs), dextran sulfate (CS-DS/DOX NPs), and hyaluronic acid (CS-HA/DOX NPs) by using ionotropic gelation or complex coacervation. CS-TP/DOX NPs were the smallest, with an average size of ~100nm and a narrow size distribution, while CS-DS/DOX and CS-HA/DOX NPs were ~200nm in size. Transmission electron microscopy clearly showed a spherical shape for all the NPs. The strong binding affinity of DOX for the multiple sulfate groups in DS resulted in a sustained release profile from CS-DS/DOX NPs at pH7.4, while CS-HA/DOX NPs exhibited faster DOX release. This trend was also present under acidic conditions, where release of DOX was significantly augmented because of polymer protonation. Compared to CS-TP/DOX or CS-DS/DOX NPs, CS-HA/DOX NPs showed superior cellular uptake and cytotoxicity in MCF-7 and A-549 cells, because of their ability to undergo CD44-mediated endocytosis. Pharmacokinetic studies clearly showed that all CS-NPs tested significantly improved DOX plasma circulation time and decreased its elimination rate constant. Consistent with the in vitro release data, CS-DS/DOX NPs exhibited a relatively better DOX plasma profile and enhanced blood circulation, compared to CS-HA/DOX or CS-TP/DOX NPs. Overall, these results demonstrated how NP design can influence their function. Taken together, CS-based polyelectrolyte complexes could provide a versatile delivery system with enormous potential in the pharmaceutical and biomedical sectors.

Two-step photochemical inorganic approach to the synthesis of Ag-CeO2 nanoheterostructures and their photocatalytic activity on tributyltin degradation

We report the extracellular synthesis of silver nanoparticles using an endophytic fungus Pestalotia sp. isolated from leaves of Syzygium cumini (L) and their antibacterial activity against human pathogenic bacteria viz. Staphylococcus aureus (ATCC-25923) and Salmonella typhi (ATCC-51812) alone and in combination with commercially available antibiotics. Detection of synthesized silver nanoparticles was carried out using UV-Visible spectrophotometer analysis, which showed a peak at 415 nm indicating the formation of nanoparticles. Further characterization includes the Fourier Transform Infra-Red spectroscopic analysis for the detection of proteins as capping agents on nanoparticles. Nanoparticle Tracking Analysis Syatem (LM-20) analysis and TEM analysis confirmed the formation of spherical and polydispersed nanoparticles in the range of 10-40 nm having average size of 12.40 nm. Biologically synthesized silver nanoparticles showed significant antibacterial activity but their efficacy was increased in combination of antibiotics like gentamycin and sulphamethizole. Silver nanoparticles in combination with gentamycin showed maximum activity (30 mm) against S. aureus followed by sulphamethizole (25 mm). Similar results were reported in case of S. typhi where silver nanoparticles in combination with gentamycin (28 mm) showed more activity than combination of silver nanoparticles and sulphamethizole (24 mm). Biosynthetic approach using an endophytic fungus is a novel way towards the development of safe, economically viable and green method for the synthesis of silver nanoparticles and thus synthesized silver nanoparticles can be used in antibacterial formulations.

Chapter 8 - Graphene–Carbon Nanotubes Modified Electrochemical Sensors

Surface plasmon resonance (SPR) sensors based on quasi-bound states in the continuum (quasi-BICs) have demonstrated extensive applications across biomedical, environmental monitoring, and industrial production sectors owing to their exceptional quality factor (Q-factor) and remarkable optical tunability.However, current research mainly focuses on the mode analysis of quasi-BICs, and insufficient attention has been paid to the relationship between quasi-BICs and the intrinsic parameters in photonic sensors such as intensity sensitivity, noise-equivalent limit of detection (LOD), and figure of merit (FOM).In this paper, a high-Q quasi-BIC is introduced into an SPR sensor, and its influence on the sensing performance, including intensity sensitivity, LOD, and FOM, is discussed in detail.The analysis shows that, compared with the traditional SPR mode, the quasi-BIC with an ultra-high and tunable Q-factor not only improves the intensity sensitivity of the device but also reduces the noise and optimizes its LOD and FOM.On this basis, we design a high-performance temperature sensor using the polydimethylsiloxane (PDMS) thermo-sensitive material.The simulation results show that the temperature sensitivity of the device is as high as -0.33 nm/C with the advantage of low noise.This theoretical analysis will provide guidance for the practical application of quasi-BICs in the field of sensing.

The present research aimed to investigate the potential of the ethanolic extract of Cladophora crispata algae for synthesizing AgNPs. The GC-mass technique was used in the identification of active compounds present in the algal ethanolic extract. The extract’s capability to synthesize silver nanoparticles was examined, as well as the formation of these nanoparticles was deduced by the color transformation of the mixture from light green to dark brown. Some of the techniques used to characterize the synthesized nanoparticles include an Ultraviolet-Visible spectrophotometer (UV-vis), Fourier Transform Infrared (FTIR) spectroscopy, a Scanning Electron Microscope (SEM), and Energy-Dispersive X-ray spectroscopy (EDX). They were also characterized by X-ray Diffraction (XRD). The antibacterial effectiveness was tested through the Agar well diffusion method. The GC-mass results indicated that the ethanolic extract of the algae contains different active compounds with different percentages of each,such as Oleic acid (11.7%), Neophytadiene (12.0%), and n-Hexadecanoic acid (283.1%). UV-vis absorption spectroscopy was used to confirm the formation of the silver nanoparticles, which appeared at a wavelength of 417nm. The XRD analysis confirmed the crystalline nature of the resulting silver nanoparticles, while SEM revealed that the AgNPs were spherical with particle sizes between 29-99 nm. EDX analysis revealed that the synthesized silver nanoparticles were composed of silver, carbon, oxygen, and chlorine. The efficacy of the synthesized silver nanoparticles was tested against four types of pathogenic bacteria, namely E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. The results demonstrated that the silver nanoparticles had a significant inhibitory capability against these pathogens.

The Phlomis bracteosa Royle ex Benth. is one of the medicinal plants used by the people of the north-western Himalayan region, India. Initially, phytochemical components of this plants have been evaluated by estimating total phenolic, flavonoid and tannin contents, and also by GCMS analysis in acetone and methanol solvents, which listed twenty-four compounds in acetone and twenty-two in methanol extract with different percentage peak areas. Later, silver nanoparticles (SNPs) were biogenically synthesized from the acetone extract of the same plant. The formation of SNPs was observed with UV-vis spectroscopy with surface plasmon resonance (SPR) at 438 nm. Further, the Fourier transform infrared spectroscopy suggested the presence of carbonyls, nitrogenous compounds and different types of hydrocarbons in SNPs. The field emission scanning electron microscopy (FESEM) and the high-resolution transmission electron microscopy suggested the spherical shape of SNPs with average size of 43.53 ± 0.71 nm. On the other hand, the energy dispersive X-ray spectroscopy depicted Ag as major element, the selected area electron diffraction and the X-ray diffraction supported crystalline nature of synthesized SNPs. The antimicrobial and antioxidant activities of both extracts (acetone and methanol) and SNPs were also studied. For the antimicrobial activity analysis, disk diffusion and broth microdilution methods were selected which displayed that plant extracts (PEs) exhibited better activity against Gram-positive bacteria and were inactive against Escherichia coli, while synthesized SNPs displayed better antimicrobial activity against all selected microorganisms. In case of antioxidant activity, by following two methods i.e., DPPH radicle scavenging and reducing power methods again SNPs expressed better antioxidant property with lower IC50 value (40.55 µg/mL) than PEs i.e., 93.48 µg/mL (acetone) and 92.57 µg/mL (methanol). Therefore, biosynthetic SNPs can be a useful strategy in the biomedical sector.

Metal nanoparticles have numerous applications in various fields of science and technology such as catalysis, optoelectronics and biomedicine.In the present study we synthesized and characterized silver nanoparticles (AgNPs) from Punica granatum peel (PGP) extract and evaluated its cytotoxic activities.The formation of nanoparticles was confirmed by visual assessment.The PGP-AgNPs was characterized by UV spectroscopy, SEM, FTIR and XRD.UV-Visible spectroscopy are important techniques to determine the formation and stability of silver nanoparticles in an aqueous solution.XRD peaks indicated that the PGP-AgNPs are crystalline in nature.FTIR spectrum of synthesized PGP-AgNPs showed the six absorption bands which indicated the presence of active functional groups in the region of 600-3500 cm -1 .The reduction of cell viability observed in this study is suggestive of anticancer effects of AgNPs synthesised from Punica granatum peel extract.Results showed reduced cell viability of cancer cell lines with increasing concentrations (10-200 g/ml) of AgNPs.In this study, silver nanoparticle showed the minimum cell viability (32.59%) and maximum inhibitions (67.41%) in 200 g/ml concentrations against HGT-1 cell line.The present study concluded that the PGP-AgNPs exhibited strong inhibitory activities against the HGT-1 cell line.

Phytofabrication of silver nanoparticles from Limonia acidissima leaf extract and their antimicrobial, antioxidant and its anticancer prophecy

Considering that nanosilver-based materials have shown to have a novel, demanding, and promising properties appropriate for a variety of biological applications, silver nanoparticles (AgNPs) have evolved into one of the most researched and examined nanostructures created from nanotechnology in recent years. Silver nanoparticles (AgNPs) have been the subject of research due to their special characteristics, and they have considerable interest in medical applications such as highly excellent antimicrobial agents even without toxic effects, and industrial applications such as inkjet inks comprising well-unified dispersions of nano-sized silver particles that are useful for creating electronic circuits. Due to the remarkable activities shown by silver nanoparticles, they have been the focus of many researchers for developing new medications with less toxic effects. In this study, we have highlighted some entitled applications of silver nanoparticles. This review will be helpful for the researchers working on silver nanoparticles.

Nanotechnology is an emerging field with vast potential in agriculture and biomedicine due to its unique physicochemical properties. Silver nanoparticles (SNPs), typically ranging from 1–100 nm, have garnered significant interest for their antimicrobial, antioxidant, and therapeutic effects. This review focuses on the synthesis, characterization, and multifunctional applications of SNPs in both the agricultural and biomedical sectors. Various synthesis methods, including biological approaches, are explored, along with the mechanisms through which SNPs exert their effects. In agriculture, SNPs have shown promise in enhancing soil quality, improving plant growth, and controlling crop diseases through nano-fertilizers and nano-pesticides. In the biomedical field, SNPs are used in antibacterial and antibiofilm treatments, wound healing, dentistry, bone and cardiac implants, and cancer therapy. Given the increasing global population and the urgent need for sustainable solutions in food and healthcare systems, SNPs offer a promising avenue for improving crop productivity and human health.

The aim of this study is to elaborate the synthesis of silver(AgNPs) and iron oxide nanoparticles (Fe2O3NPs) via green nanotechnology by Elwendia persicum seed extracted and analyzed their antibacterial activity against Staphylococcus aureus. E. persicum is non-toxic and less expensive, having good antibacterial activity. Multi-drug resistance is a growing problem in treating bacteria such as Staphylococcus aureus. There is an urgent need to develop alternative, cost-effective, non-toxic and efficient antimicrobial agents to overcome antimicrobial resistance. Advances in nanotechnology allow the synthesis of green nanoparticles, which can be prepared for controlling bacterial growth. The evolution of antibiotics, which are mostly useful against bacteria and drug-resistant microorganisms. For this purpose, the development of green NPs (silver and iron oxide) has been planned with the objective of evaluating the antibacterial effect of green silver and iron oxide nanoparticles on Staphylococcus aureus. The formation of nanoparticles was confirmed by visual detection by a change in the color of the solution. The characterization of these nanoparticles was done by zeta sizer, zeta potential, UV-Visible spectrometry, FTIR, and scanning electron microscopy to determine the precise formation of silver and iron oxide nanoparticles. The antimicrobial mechanism was fined by the well diffusion method. The results confirmed that synthesized silver and iron oxide nanoparticles have good antibacterial activity against Staphylococcus aureus.

Silver sols that contain mainly small silver nanoparticles (up to 10 nm) have been synthesized by a method of electrolysis using silver electrodes under conditions of altered current polarity in the sodium polyacrylate (NaPA) solutions. It is shown that the values of the current of the anode dissolution of silver increase with increasing of NaPA concentration and the dependence of іanode—E is linear. Its proposed multistage scheme of formation stabilized by polyacrylate anion (PA−) silver nanoparticles that includes (1) ionization of silver and the complexation of produced Ag+ ions with polyacrylate, (2) cathode reduction of silver ions from the complex, (3) formation of PA− stabilized nanoclusters, and (4) aggregation of nanoclusters and formation of nanoparticles is proposed. Using UV-vis spectroscopy, observable rate constants of the nucleation and the growth of silver nanoparticles depending on temperature and sodium polyacrylate concentration have been estimated. It was found that the formation of silver nanoparticles is carried out in electrode space and is limited by diffusion. The correlations of the size of silver nanoparticles with observable rates of the nucleation and growth were shown.