Circulating tumour cells (CTCs) are active participants in the metastasis process and account for ∼90% of all cancer deaths. As CTCs are admixed with a very large amount of erythrocytes, leukocytes, and platelets in blood, CTCs are very rare, making their isolation, capture, and detection a major technological challenge. Microfluidic technologies have opened-up new opportunities for the screening of blood samples and the detection of CTCs or other important cancer biomarker-proteins. In this study, the authors have reviewed the most recent developments in microfluidic devices for cells/biomarkers manipulation and detection, focusing their attention on immunomagnetic-affinity-based devices, dielectrophoresis-based devices, surface-plasmon-resonance microfluidic sensors, and quantum-dots-based sensors.

Elucidation of the role of silver nanoparticles (AgNPs) in combating bacterial infection is important for the development of new antimicrobial compounds. In this study, several key factors underlying biological effects of biogenic AgNPs were investigated on recombinant Escherichia coli (XL1-Blue) which contains a reporter gene encoding β-galactosidase enzyme. Biogenic AgNPs were prepared from the tea decoction. Cytotoxicity effects were profound on the bacteria tested by the synthesised NPs. The β-galactosidase activity of the released intracellular proteins in the supernatant of E. coli was used as a measure of membrane damage and cellular leakage. Occurrence of a significant amount of β-galactosiadase activity in the supernatant of treated cells clearly demonstrated the formation of holes in the bacterial membrane. Scanning electron microscope pictures visibly indicated destruction of the membrane of the bacteria, which further confirmed membrane damage. The synthesised NPs caused damage of E. coli genomic DNA in a dose dependent manner.

The current study was performed to synthesize stable, eco-friendly and bio-compatible silver nano-particles (AgNPs) of Agave americana, Mentha spicata and Mangifera indica leaves and to screen them for biological activities. The ultraviolet-visible spectroscopic analysis revealed that λ-max for AgNPs range from 350–500 nm. All AgNPs possessed polycrystalline structure as notified as intense graphical peaks in complete spectrum of 20 values ranging from 10–80° in X-ray diffraction measurements and supported by scanning electron microscopy data. The size of the nano-particles was confirmed by transmission electron microscopy (30–150 nm). Mass loss at variable temperatures was evaluated by simultaneous thermogravimetric and differential thermal analysis revealed reduction in mass and activity of compounds was notified by temperature increase from 200 to 800 °C, thus concluding it as thermally sensitive compounds. A. americana AgNPs showed significant (96%) activity against Methicillin resistant Staphylococcus aureus, Escherichia coli (95%) and Fusarium oxysporum (89%). Good antioxidant activity was shown by M. spicata AgNPs at 300 µl (79%). M. indica AgNPs showed significant phytotoxic activity (88%) at highest concentration. No haemagglutination reaction was observed for the test samples. The above results revealed that AgNPs synthesized from selected plant species possesses significant antimicrobial and phytotoxic effect.

The biosynthesis of silver nanoparticles (AgNPs) has been proved to be a cost effective and environmental friendly approach toward chemical and physical methods. In the present study, biosynthesis of AgNPs was carried out using aqueous extract of Zea mays (Zm) husk. The initial colour change from golden yellow to orange was observed between 410 and 450 nm which confirmed the synthesis of AgNPs. Also, dynamic light scattering-particle size analysis confirmed the average size to be 113 nm and zeta potential value of −28 kV. The morphology of synthesised ZmAgNPs displayed flower-shaped structure, X-ray diffraction pattern revealed the strongest peaks at 2θ = 38.6° and 64° which proved that the nanoparticle has the face centred crystalline structure. The Fourier transform infrared spectroscopy results showed strong absorption bands at 1394.53, 2980.02 and 2980.02 cm⁻¹ due to the presence of alkynes, carboxylic acids, alcoholic and phenolic groups. The maximum zone of inhibition was observed against Salmonella typhi (22 mm) and Candida albicans (18 mm). The synthesised nanoparticles exhibited more free radical scavenging activity than the aqueous plant extract. This is the first report on the synthesis of AgNP from Zm husk, delivers the efficient and stable ZmAgNPs through simple feasible approach toward green biotechnology.

Biological routes of synthesising metal nanoparticles (NPs) using microbes have been gaining much attention due to their low toxicity and eco-friendly nature. Pseudomonas aeruginosa JP2 isolated from metal contaminated soil was evaluated towards extracellular synthesis of silver NPs (AgNPs). Cell-free extract (24 h) of the bacterial isolate was reacted with AgNO₃ for 24 h in order to fabricate AgNPs. Preliminary observations were recorded in terms of colour change of the reaction mixture from yellow to greyish black. UV-visible spectroscopy of the reaction mixture has shown a progressive increase in optical densities that correspond to peaks near 430 nm, depicting reduction of ionic silver (Ag⁺) to atomic silver (Ag⁰) thereby synthesising NPs. X-ray diffraction spectra exhibited the 2θ values to be 38.4577° confirming the crystalline and spherical nature of NPs [9.6 − 26.7 (Ave. = 17.2 nm)]. Transmission electron microscopy finally confirmed the size of the particles varying from 5 to 60 nm. Moreover, rhamnolipids and proteins were identified as stabilising molecules for the AgNPs through Fourier transform-infrared spectroscopy. Characterisation of bacterial crude and purified protein fractions confirmed the involvement of nitrate reductase (molecular weight 66 kDa and specific activity = 3.8 U/mg) in the Synthesis of AgNPs.

A green facile method has been successfully used for the synthesis of graphene oxide sheets decorated with silver nanoparticles (rGO/AgNPs), employing graphite oxide as a precursor of graphene oxide (GO), AgNO₃ as a precursor of Ag nanoparticles (AgNPs), and geranium (Pelargonium graveolens) extract as reducing agent. Synthesis was accomplished using the weight ratios 1:1 and 1:3 GO/Ag, respectively. The synthesised nanocomposites were characterised by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, UV-visible spectroscopy, Raman spectroscopy, energy dispersive X-ray spectroscopy and thermogravimetric analysis. The results show a more uniform and homogeneous distribution of AgNPs on the surface of the GO sheets with the weight ratio 1:1 in comparison with the ratio 1:3. This eco-friendly method provides a rGO/AgNPs nanocomposite with promising applications, such as surface enhanced Raman scattering, catalysis, biomedical material and antibacterial agent.

The present study focuses on the biosynthesis of gold nanoparticles (AuNPs) using Streptomyces coelicoflavus (S. coelicoflavus) SRBVIT13 isolated from marine salt pan soils collected from Ongole, Andhra Pradesh, India. The biosynthesised AuNPs are characterised by UV–visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy and energy-dispersive X-ray analysis. Transmission electron microscopy study suggests that the biosynthesised AuNPs are spherical in shape within a size range of 12–20 nm (mean diameter as 14 nm). The anti-type II diabetes activity of AuNPs is carried out by testing it in vitro α-glucosidase and α-amylase enzyme inhibition activity and in vivo postprandial anti-hyperglycemic activity in sucrose and glucose-loaded streptozotocin induced diabetic albino Wister rats. AuNPs has shown a significant inhibitory activity of 84.70 and 87.82% with IC₅₀ values of 67.65 and 65.59 μg/mL to α-glucosidase and α-amylase enzymes, while the diabetic rats have shown significant reduction in the post postprandial blood glucose level by 57.80 and 88.09%, respectively compared with control group after AuNPs treatment at the concentration of 300 and 600 mg/kg body weight. Hence, this biosynthesised AuNPs might be useful in combating type II diabetes mellitus for the betterment of human life.

In this article, a patch-clamp low noise current amplification based on nanoparticles plasmonic radiation is analyzed. It is well-known, a very small current is flowing from different membrane channels and so, for extra processing the current amplification is necessary. It is notable that there are some problems in traditional electronic amplifier due to its noise and bandwidth problem. Because of the important role of the patch-clamp current in cancer research and especially its small amplitude, it is vital to intensify it without adding any noises. In this study, the current amplification is performed firstly: from the excitement of nanoparticles by the patch-clamp pico-ampere current and then, the effect of nanoparticles plasmonic far-field radiation on conductor's carriers, which will cause the current amplification. This relates to the plasmonic-photonic coupling and their effect on conductor carriers as the current perturbation agent. In the steady state, the current amplification can reach to 1000 times of initial level. Furthermore, we investigated the nanoparticles morphology changing effect such as size, nanoparticles inter-distance, and nanoparticles distance from the conductor on the amplifier parameters. Finally, it should note that the original aim is to use nanoparticles plasmonic engineering and their coupling to photonics for output current manipulating.

This study reports the unprecedented, novel and eco-friendly method for the synthesis of three-dimensional (3D) copper nanostructure having flower like morphology using leaf extract of Ficus benghalensis. The catalytic activity of copper nanoflowers (CuNFs) was investigated against methylene blue (MB) used as a modal dye pollutant. Scanning electron micrograph evidently designated 3D appearance of nanoflowers within a size range from 250 nm to 2.5 μm. Energy-dispersive X-ray spectra showed the presence of copper elements in the nanoflowers. Fourier-transform infrared spectra clearly demonstrated the presence of biomolecules which is responsible for the synthesis of CuNFs. The catalytic activity of the synthesised CuNFs was monitored by ultraviolet–visible spectroscopy. The MB was degraded by 72% in 85 min on addition of CuNFs and the rate constant (k) was found to be 0.77 × 10⁻³ s⁻¹. This method adapted for synthesis of CuNFs offers a valuable contribution in the area of nanomaterial synthesis and in water research by suggesting a sustainable and an alternative route for removal of toxic solvents and waste materials.

This paper investigated the green synthesis of silver nanoparticles (AgNPs) using aqueous extract of silky hairs of corn (Zea mays L.) which is a waste material of the crop, as both a reducing and stabilising/capping agent. The AgNPs were characterised by UV-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The average size of AgNPs was found to be 249.12 nm. The AgNPs displayed strong antibacterial activity against five different foodborne pathogenic bacteria with diameter of inhibition zones ranged between (9.23 − 12.81 mm). It also exhibited potent synergistic antibacterial activity together with standard antibiotics, kanamycin (10.6 − 13.65 mm inhibition zones) and rifampicin (10.02 − 12.86 mm inhibition zones) and anticandidal activity with amphotericin b (10.57 − 13.63 mm inhibition zones). The AgNPs exhibited strong antioxidant activity in terms of nitric oxide scavenging (IC₅₀ 91.56 µg/mL), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging (IC₅₀ 115.75 µg/mL), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging (IC₅₀ 385.87 µg/mL), and reducing power (IC_0.5 23.14 µg/mL). This study demonstrated the synthesis of spherical AgNPs with strong antibacterial, anticandidal and antioxidant properties that could potentially be utilised in the biomedical, cosmetic, food and pharmaceutical industries.

Bovine horns are durable that they can withstand an extreme loading force which with special structures and mechanical properties. In this study, the authors apply quasi-static nanoindentation and modulus mapping techniques to research the nanomechanical properties of bovine horn in the transverse direction (TD) and longitudinal direction (LD). In quasi-static nanoindentation, the horn's modulus and hardness in the inner layer and the outer layer demonstrated a gradual increase in both TD and LD. Laser scanning confocal microscopy revealed microstructure in the horn with wavy morphology in the TD cross-section and laminate in the LD cross-section. When using tensile tests or quasi-static nanoindentation tests alone, the anisotropy of the mechanical properties of bovine horn were not obvious. However, when using modulus mapping, storage modulus (E′), loss modulus (E″) and loss ratio (tan δ) are clearly different depending on the position in the TD and LD. Modulus mapping is proposed as accurately describing the internal structures of bovine horn and helpful in understanding the horn's energy-absorption, stiffness and strength that resists forces during fighting.

Wound healing requires a series of cellular events and a cascade of co-ordinated and systemic biochemical events. Silver nanoparticles possess many beneficial properties for wound management including antibacterial, anti-inflammatory and pro-healing properties. In this study, the authors investigated the wound healing properties of Cinnamomum verum extract mediated nanosilver (CENS) particles in comparison with 1% povidone iodine, citrate mediate NS and CE treatments. The topical application of CENS showed good antibacterial activity and accelerated wound healing with complete epithelialisation and normal re-growth of hair in all three models of study: namely, excision, incision and dead space models in rats compared with all other treatments. CENS was also found to promote collagen synthesis, stabilise wound besides countering oxidative stress and stimulating cellular proliferation CENS could be a novel therapeutic agent for wound management.

Silver nanoparticles (AgNPs) were biosynthesized via a green route using ten different plants extracts (GNP1- Caryota urens, GNP2-Pongamia glabra, GNP3- Hamelia patens, GNP4-Thevetia peruviana, GNP5-Calendula officinalis, GNP6-Tectona grandis, GNP7-Ficus petiolaris, GNP8- Ficus busking, GNP9- Juniper communis, GNP10-Bauhinia purpurea). AgNPs were tested against drug resistant microbes and their biofilms. These nanoparticles (NPs) were characterised using UV-vis spectroscopy, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction and Image J software. Most of the AgNPs were distributed over a range of 1 of 60 nm size. The results indicated that AgNPs were antibacterial in nature without differentiating between resistant or susceptible strains. Moreover, the effect was more prominent on Gram negative bacteria then Gram positive bacteria and fungus. AgNPs inhibited various classes of microbes with different concentration. It was also evident from the results that the origin or nature of extract did not affect the activity of the NPs. Protein and carbohydrate leakage assays confirmed that the cells lysis is one of the main mechanisms for the killing of microbes by green AgNPs. This study suggests that the action of AgNPs on microbial cells resulted into cell lysis and DNA damage. Excellent microbial biofilm inhibition was also seen by these green AgNPs. AgNPs have proved their candidature as a potential antibacterial and antibiofilm agent against MDR microbes.