Search results

This paper aims to clarify the relationship between the performance of the metal nanoparticles and the sensitivity of the fiber surface plasma resonance (SPR) sensor. It proposes modeling the sensing effects of a single-mode fiber SPR sensor with a cone angle structure decorated with metal nanoparticles. This study uses the metal nanoparticles to the realize enhanced sensitivity of refractive index sensing.

This paper opted for an exploratory study using a simulation approach of finite-difference time-domain (FDTD). Specifically, the effect of size, the material and the shape of the metal nanoparticle on sensing performance are investigated theoretically.

In conclusion, it is evident that the localized SPR (LSPR) effect weakens as the diameter of the gold nanosphere increases, the SPR effect enhances and the SPR sensitivity increases first and then decreases. The metal nanoparticle with the different materials and different shapes also have different LSPR and SPR sensitivity and wavelength length dynamic range. The investigation shows that, by changing parameters, the reflection spectra of the fiber SPR sensor exhibit an obvious transition from LSPR to SPR characteristics, and enhanced sensitivity of the refractive index is realized.

This paper fulfills an identified need to study how the sensitivity of the fiber SPR sensor can be enhanced by the metal nanoparticle. After the optimization of parameters, the sensitivity of 5,140 nm/RIU is achieved, which provides a new research direction for sensitivity enhancement of fiber SPR sensor.

Functionalization of organic cotton fabrics (OCFs) by in situ deposition of chitosan reduced-stabilized silver nanoparticles (AgNPs). No other toxic chemicals used to warrant an ecofriendly synthesis protocol. Human toxicity of silver systematically avoided to use as textile clothing. Primary colors (nearly-red, yellow and blue) were imparted on OCFs via localized surface plasmon resonance (LSPR) of AgNPs. Decent mechanical properties and laundering durability in terms of antibacterial/fastness test improved mechanical properties.

Silver nanoparticles can be synthesized by using silver nitrate along with commercially available chitosan. Due to the surface LSPR property of silver nanoparticles, it exhibits versatile colors depending on the synthesizing procedures. The coloration occurs due to the electrostatic interaction between the AgNPs and chitosan-treated OCF. The nanotreated fabrics provide excellent mechanical properties with improved antibacterial effects.

X-ray fluorescence (XRF) analysis quantifies the developed materials in the substrates. Scanning electron microscopy (SEM) characterization indicates the appearance and morphologies of silver nanoparticles into the fabric surface after the coloration process. It proves that the treated cotton knit fabric exhibits the LSPR optical features of AgNPs. The antibacterial and mechanical properties confirm the improved functionality of products.

Improved mechanical properties, antibacterial performances and coloration effects on organic cotton substrates in terms of chitosan-mediated nanosilver are not yet studied.

In this contribution, the aim is to present a nanoparticle device, operating in the visible regime based on the localized surface plasmon resonance (LSPR) phenomenon.

The nanoparticle electromagnetic properties are evaluated by a new analytical model and compared to the results obtained by numerical analysis.

A near-field enhancement is obtained by arranging the nanoparticles in a linear array. Analytical formulas, describing such enhancement, are presented.

The results demonstrate the possibility to use the proposed device for medical diagnostics and optoelectronics applications.

This paper aims to study the sensitivity enhancement effect of the gold nanorod on fiber surface plasmon resonance (SPR) sensor. It proposes modeling the sensing effects of fiber SPR sensor decorated with metal nanoparticles. By using simulation and experiment, the sensitivity enhancement effect of the gold nanorod was studied and demonstrated.

The paper opted for an exploratory study using simulation approach of finite-difference time-domain. Specifically, the effect of ratios and aspect ratios of gold nanorod on sensing performance are investigated theoretically. Based on the mathematical models, the validation experiments by using the gold nanorod with the aspect ratios of 5.1 were done to verify the sensitivity enhancement effect of the gold nanorod.

In conclusion, it is evident that with the increases of the aspect ratios, the sensing sensitivity of the refractive index increases first, then gradually stabilizes or decreases. After parameter optimization, the ratios and aspect ratios of gold nanorod are chosen to be 8 nm and 12.5, respectively, which makes the optimal refractive index sensitivity of 4465.53 nm/RIU be realized. In addition, the validation experiments by using the gold nanorod with the aspect ratios of 5.1 verify the sensitivity enhancement effect of the gold nanorods.

This paper proposes and demonstrates a new method for the sensitivity enhancement of fiber SPR sensor. After parameter optimization, the maximum sensitivity of 4465.53 nm/RIU was achieved by using 8 nm gold nanorods with the aspect ratios of 12.5. To verify the sensitivity enhancement of the gold nanorods, the authors also did the validation experiments. The testing results indicated that after the decoration of the gold nanorods, the sensitivity of the sensing probe increases from 2190.57 nm/RIU to 2693.24 nm/RIU, which demonstrates the sensitivity enhancement effect of the gold nanorods.

This paper aims to discover the novelties in biosensor fabrication brought about by breakthroughs in nanomaterials and process techniques, the resulting enhancement in biosensor functionalities, new applications and future possibilities.

The impact of nanotechnology on biosensor advancement has been examined. Different directions of biosensor research in the nano era have been highlighted. These include the efforts made through nanotechnology to improve the performance parameters of the existing biosensors, and for implementation of innovative biosensor concepts.

Nanotechnology is a key technology in biosensor development. It has permeated into the biosensor field and brought in its wake far‐reaching changes.

Biosensor science and engineering are central to virtually all aspects of life including medical diagnostics, environmental monitoring and biotechnological process control. Therefore, the progress in biosensors brought about by nanotechnology influences one's everyday life.

The study helps in understanding the applications of nanotechnology in fabricating a new generation of biosensors with improved characteristics. It provides information of value to those involved in biosensor research.

This paper aims to focus on research work related to metamaterial-based sensors for material characterization that have been developed for past ten years. A decade of research on metamaterial for sensing application has led to the advancement of compact and improved sensors.

In this study, relevant research papers on metamaterial sensors for material characterization published in reputed journals during the period 2007-2018 were reviewed, particularly focusing on shape, size and nature of materials characterized. Each sensor with its design and performance parameters have been summarized and discussed here.

As metamaterial structures are excited by electromagnetic wave interaction, sensing application throughout electromagnetic spectrum is possible. Recent advancement in fabrication techniques and improvement in metamaterial structures have led to the development of compact, label free and reversible sensors with high sensitivity.

The paper provides useful information on the development of metamaterial sensors for material characterization.

This paper aims to assess the impact of nanotechnology on sensors. Examples of recent nanosensor developments are given and future prospects are briefly considered.

The purpose of this paper is to contribute an analytical and numerical study of a new type of nanoshell particles operating in the visible regime.

The structure consists of a core/shell particle, arranged in a planar array configuration, with a polymethyl methacrylate (PMMA)-graphene core and gold thin shell.

By exploiting the proposed analytical model the design of a metamaterial-based sensor, operating in the optical frequency range, for the detection of tissue diseases is shown.

Full-wave simulations confirm the capability of the proposed sensor to identify different compounds by refractive index measurement.

The purpose of this paper is to explore the direct and exclusive effects of this rather unconventional monetary policy on financial markets, economic activity and labor markets across the Eurozone.

Using a range of variables, the analysis employed the Markov-switching dynamic regression methodological approach.

The findings provided evidence in favor of the reduction of short- and log-term credit spreads, increased stock prices, improved market expectations, recovered labor market conditions and economic productivity, while the primary transmission channel of the quantitative easing policy is the expectations channel.

The novelties of this paper are twofold: it makes use of a wide data set to investigate the effect of economic and financial variables on productivity, labor markets, bond markets and equity markets in the Eurozone; and the analysis focuses on the direct effects of monetary base increases on the Eurozone economy, as well as on Eurozone financial markets.

This paper aims to present an analytical investigation of energy and exergy performance on a solar flat plate collector (SFPC) with Cu-CuO/water hybrid nanofluid, Cu/water and CuO/water nanofluids as collector running fluids.

Heat transfer characteristics, pressure drop and energy and exergy efficiencies of SFPC working on these nanofluids are investigated and compared. In this study, a comparison is made by varying the mass flow rates and nanoparticle volume concentration. Thermophysical properties of hybrid nanofluids are estimated using distinctive correlations available in the open literature. Then, the influence of these properties on energy and exergy efficiencies of SFPC is discussed in detail.

Energy analysis reveals that by introducing the hybrid nanoparticles in water, the thermal conductivity of the working fluid is enhanced by 17.52 per cent and that of the individual constituents is enhanced by 15.72 and 15.35 per cent for Cu/water and CuO/water nanofluids, respectively. This resulted in 2.16 per cent improvement in useful heat gain for hybrid nanofluid and 1.03 and 0.91 per cent improvement in heat gain for Cu/water and CuO/water nanofluids, respectively. In line with the above, the collector efficiency increased by 2.175 per cent for the hybrid nanofluid and 0.93 and 1.05 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Exergy analysis elucidates that by using the hybrid nanofluid, exergy efficiency is increased by 2.59 per cent, whereas it is 2.32 and 2.18 per cent enhancement for Cu/water and CuO/water nanofluids, respectively. Entropy generation is reduced by 3.31, 2.35 and 2.96 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, as compared to water.

However, this is associated with a penalty of increment in pressure drop of 2.92, 3.09 and 2.74 per cent for Cu-CuO/water, Cu/water and CuO/water nanofluids, respectively, compared with water.

It is clear from the analysis that Cu-CuO/water hybrid nanofluids possess notable increment in both energy and exergy efficiencies to use them in SFPCs.