Humidity Vapor Research Articles

Structural, optical and sensing properties of ZnS thick films deposited by RF magnetron sputtering technique at different powers

PurposeThis study aims to carry out the deposition of zinc sulfide (ZnS) thick films on glass and silicon (100) substrates using radio frequency (RF) magnetron sputtering method at different powers. Film structure has been analyzed by X-ray diffraction (XRD); the patterns showed that the films possesses a cubic structure with (111) preferred orientation. Photoluminance (PL) intensity of the films has been related to the crystallinity, which is varied with the power.Design/methodology/approachScanning electron microscope (SEM) images have been used to discover the films’ morphology. The stoichiometry has been confirmed by energy dispersive X-ray spectroscopy (EDX) analysis. MicroRaman spectroscopy has been used to validate the film structure. Gas-sensing studies were carried out by means of a static gas chamber to sense acetone, ethanol, methanol, H2O and NH3 vapor in air ambient.FindingsZnS has a stoichiometric and cubic structure. The band gaps and photoluminance intensity of the films are correlated with the crystallinity, which is varied with the power. The EDX analysis approved the stoichiometry of the prepared films. Acetone, ethanol, humidity (H2O), methanol and NH3 vapor gases were used to justify the sensing properties at 25°C of the thickest ZnS film.Originality/valueHigh-quality ZnS films have been obtained at different powers without annealing. Gases sensing properties at 25°C are justified for deposited ZnS films using acetone, ethanol, humidity (H2O), methanol and NH3 vapor gases. It reveals good response for NH3 and humidity vapors at room temperature; the sensing functioning at this temperature was attractive in recent research.

Partial melting time model verification of a levitated ice particle

Experimental and analytical results modeling partially melting ice particles are presented in this research paper. The partially melting behavior of ice particles is of interest in the context of aircraft engines, as glaciated ice crystals partially melt inside the engine to potentially refreeze. The multi-phase flow process is complex and requires experimentally verified modeling tools to predict ice crystal ice accretion. In this study, a total of 14 experimental test cases were conducted under a controlled environment. The partially melting state was quantified using a luminescence technique with the assistance of acoustic levitation of the droplets. Analytical modeling of the melting process was then conducted. The model includes important parameters such as ambient temperature, relative humidity, or saturated vapor density into consideration to predict the partial melting state of the glaciated water droplets subjected to convective heating. The proposed model is effective in capturing the general trend of the melting curves obtained from the experimental data. The predictions of overall melting time for the entire 14 cases were found to be accurate with 4% mean discrepancy between model and experimental data for ice particles greater than 400 μm.

Association Between Air Temperature and the Incidence of Acute Coronary Heart Disease in Northeast China.

AimThe aim of this study was to examine the association between air temperature and incidence of acute coronary heart disease in Northeast China.MethodsWe obtained coronary heart disease (CHD) daily hospitalization data from January 2017 to June 2019, and collected meteorological data including average daily air temperature, air pressure, relative humidity, wind velocity, sunshine duration and water vapor pressure, for the same period. Totally, This study included data from 6775 patients with CHD.ResultsAfter adjusting for confounding factors, low air temperature was inversely associated with CHD. Additionally, in the warm season (April–September), the number of daily hospital admissions for CHD was higher (≥24.2°C) if the average daily air temperature was low (≤15.4°C).ConclusionLow air temperature might be a risk factor for CHD among the elderly, especially in the warm season.

Optical properties of dust and crop burning emissions over India using ground and satellite data

Dust storms during the pre-monsoon season (April–June) and crop residual burning events during the post-monsoon season (mid-October–mid-November) are common every year over the Indo-Gangetic plains (IGP). In this paper, we have compared dust storm and crop burning aerosols characteristics for the years 2016, 2017 and 2018 using ground and satellite data. CALIPSO data show that dust layers extended from the ground upto an altitude of about 5 km and the smoke from crop burning upto the height of 2 km. Characteristics of dust and crop burning aerosols show pronounced difference based on Kanpur AERONET data. Dominance of coarse particles (0.6–15 μm) during dust storms (pre-monsoon season), while fine particles (0.05–0.6 μm) dominate during crop residual burning. The spectral variations of single scattering albedo (SSA) during dusty days and crop burning days show low and high fractions of anthropogenic aerosols. We have also observed the impact of dust particles on Himalayan snow (cover, albedo and reflectance) and meteorological parameters (relative humidity and water vapor) on the surface and lower atmosphere using MODIS data and AIRS data at different pressure levels. Pronounced aerosols behaviors of the crop residual burning event coincided with Diwali festival on 30–31 October 2016 were observed. Our detailed analysis combining ground and satellite observations provides better understanding of aerosol optical and microphysical properties of dust storms and crop residual burnings. The results will be valuable in monitoring surrounding environment, identifying the emission source and dynamics of dust storms and crop burning emissions over India, especially in the IGP.

Variations in sap flow of Zenia insignis under different rock bareness rate in North Guangdong, China

Understanding the impact of rock bareness on the transpiration in karst plants is essential to karst rocky desertification control and sustainable management of plantation in karst area. This study focused on the variations in sap flow of Zenia insignis caused by different rock bareness rate, and the impact of climate factors, soil water content (SWC) and leaf area index (LAI) on transpiration in karst plants, by continuously measuring sap flux densities (Fd) of 12 sample trees using thermal dissipation probes and monitoring micrometeorology and SWC on a typical karst hill in north Guangdong of China during the year of 2016. Results show that: (1) the maximum hourly sap flux density occurred at 11:00–14:00 and the peak daily sap flux density occurred in September. (2) Sap flow density of Zenia insignis increased with rock bareness rate at all hourly, daily and monthly scales, with the sequence of extremely severe > severe > moderate > mild rock bareness. (3) The transpiration of Zenia insignis is controlled by different factors at different temporal scales. At hourly scale, transpiration was highly (n=144, R2>0.72) correlated to Solar radiation (Rs), Air temperature (Ta), relative humidity (RH), and water vapor pressure deficit (VPD). At daily scale, transpiration was greatly (77=366, R2>0.31) affected by Solar radiation (Rs), Air temperature (Ta), and water vapor pressure deficit (VPD). While at monthly scale, transpiration was mainly (n=12, R2=0.8s) controlled by LAI. Our study proved that Zenia insignis has a good physiecological adaption to fragile karst environment, and Zenia insignis plantation has long-term sustainability even in extremely rocky landscapes. The results may provide scientific basis for plantation management and ecological restoration in karst area.

Global seasonal variations of the near-surface relative humidity levels on present-day Mars

We investigate the global seasonal variations of near-surface relative humidity and relevant attributes, like temperature and water vapor volume mixing ratio on Mars using calculations from modelled and measurement data. We focus on 2 AM local time snapshots to eliminate daily effects related to differences in insolation, and to be able to compare calculations based on modelling data from the Laboratoire de Météorologie Dynamique Mars General Circulation Model with the observations of Mars Global Surveyor Thermal Emission Spectrometer. We study the seasonal effects by examining four specific dates in the Martian year, the northern spring equinox, summer solstice, autumn equinox, and winter solstice. We identify three specific zones, where the near-surface relative humidity levels are systematically higher than in their vicinity regardless of season. We find that these areas coincide with low thermal inertia features, which control surface temperatures on the planet, and are most likely covered with unconsolidated fine dust with grain sizes smaller than ∼ 40 μm. By comparing the data of relative humidity, temperature and water vapor volume mixing ratio at three different heights (near-surface, ∼ 4 m and ∼ 23 m above the surface), we demonstrate that the thermal inertia could play an important role in determining near-surface humidity levels. We also notice that during the night the water vapor levels drop at ∼ 4 m above the surface. This, together with the temperature and thermal inertia values, shows that water vapor likely condenses in the near-surface atmosphere and on the ground during the night at the three aforementioned regions. This condensation may be in the form of brines, wettening of the fine grains by adsorption or deliquescence. This study specifies areas of interest on the surface of present day Mars for the proposed condensation, which may be examined by in-situ measurements in the future.

Poly(vinylidene fluoride) membranes fabricated by vapor‐induced phase separation (VIPS) for the adsorption removal of VB12 from aqueous solution

ABSTRACTPoly(vinylidene fluoride) (PVDF) membranes without any additives were fabricated by a vapor‐induced phase separation method and applied to the adsorption separation of vitamin B12 (VB12) from aqueous solution. The effects of preparation conditions including PVDF concentration in dope, vapor humidity, and exposure time on the morphologies, mechanical strength, adsorption, and permeation performances are investigated in detail. The results indicate that the PVDF membranes have a uniform spongy structure without macrovoids. The lower polymer concentration, relatively higher humidity, and longer exposure time easily leads to the formation of larger polymer nodules in the membrane matrix and lower mechanical strength of membranes. The resulted PVDF membranes exhibit superior separation efficiency for both static and dynamic adsorption for VB12. In the ultrafiltration (adsorption)‐regeneration cycles, the permeation flux remains above 2500 L m−2 h−1 bar−1 and the VB12 removal ratio is above 92% after six cycles. The prepared PVDF membranes show superior adsorption capacities to other traditional adsorbents (such as activated carbons, nanoclay, etc.) for VB12 removal. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48179.

A study on the effects of soil moisture, air humidity, and air temperature on wind speed threshold for dust emissions in the Taklimakan Desert

Soil and the atmospheric conditions are important factors that affect wind speed threshold of surface dust emissions. Based on the observed data of surface dust emissions in the Taklimakan Desert collected from March 2008 to February 2018, the effects of soil moisture, air humidity (vapor pressure), and air temperature on wind speed threshold were analyzed in this study. The results showed that the accumulated time of dust emissions over the decade was 3609.8 h, thereby accounting for 4.1% of the total observation time. In addition, the duration of dust emission in the four seasons were consistent with the pattern of summer > spring > autumn > winter. When the soil moisture is above 3.0–4.0%, the wind speed threshold for dust emission increases with increasing soil moisture. When the vapor pressure is above 10–15 kPa, the wind speed threshold for dust emission increases with increasing vapor pressure. There was a negative correlation between air temperature and the wind speed threshold for dust emission. When the air temperature was higher than 0.0 °C, the soil moisture decreased with increasing air temperature, and the wind speed threshold for dust emission was lower.

Study of changing the intensity of photoluminescence spectra as a humidity sensor for graphene on porous silicon

Humidity is the one of physical quantities that widely measured and is of very important in a many fields. In this paper, the ultra sensor of humidity was created using modified porous layer of silicon (PS), by thin films of reduction graphene oxide sheets (rGO). The electrochemical method was applied to exfoliation electrodes of graphite for preparing rGO sheets in peeling solution Acidic about PH = 4.6. p-type of Silicon waver (Si) was used for formulating PS samples using electrochemical etching (ECE) process. three etching current density 2, 4 & 6 mA/cm2 were used and fixed the other parameters such as Hydrofluoric acid HFc concentration was 15%, and time of etching about 15 min. All the samples of PS and rGO/PS were tested as humidity sensor. the structure characteristic, morphological properties and surface chemical bonds configuration were described by X-ray diffraction (XRD)و Scanning electron microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) consequently, also the Photoluminescence (PL) tests were conducted by using system of sensor test, the measurements of PL in a controlled humidity atmosphere (mixing gas of Nitrogen with humidity (vapor of water) were performed for examining the sensor response to the water vapor. The results showed that all samples revealed that the PL intensities were increased while rGO sheets deposited on the surface layer of PS, and improved the sensitivity of PS as humidity sensor.

Superhydrophilic, Underwater Superoleophobic, and Highly Stretchable Humidity and Chemical Vapor Sensors for Human Breath Detection.

Humidity and chemical vapor sensors have promising applications in the field of environment protection, human healthcare, and so forth. It is still challenging to develop sensor materials that can serve as both humidity and chemical vapor sensors with high sensitivity, low detection limit, and excellent stretchability, repeatability, and reliability. In this study, a flexible, stretchable, and conductive nanofiber composite (CNC) with superhydrophilicity and underwater superoleophobicity is prepared by acidified carbon nanotube (ACNT) decoration onto the thermoplastic polyurethane (PU) nanofiber surface. ACNT introduction increases both the Young's modulus and tensile strength and almost maintains the superelasticity of the PU nanofibrous membrane. The as-obtained CNC could be used to detect both moisture and chemical vapors. When used as the humidity sensor, ACNTs can absorb surrounding water molecules and thus increase their resistance. On the other hand, the PU can be swollen by different chemical vapors, which can, to a different extent, damage the conductive network inside the composite and cause the increase of the composite resistance. The CNC can be integrated with a mask for real-time detection of human respiration. The CNC-based chemical vapor sensor possesses low detection limit, quick response, good selectivity, and excellent recyclability (even in a high humid environment) and has potential applications in monitoring biomarker gases from human breath.

Simultaneous and Reversible Triggering of the Phase Transfer and Luminescence Change of Amidine-Modified Carbon Dots by CO2

The ability to reversibly manipulate the surface nature of luminescent nanoparticles upon external stimulation enables the development of advanced optical probes for biological sensing and data encoding. Herein, we report the synthesis of a new class of smart carbon dots (CDs) via surface modification of amine-enriched CDs with CO2-responsive groups of amidine. We present that alternative CO2 and N2 bubbling can not only lead to a reversible phase transfer of the CDs between an organic phase and an aqueous phase but also give rise to a corresponding reversible luminescence change between blue and cyan-green. We attribute these observations to changes in both the surface chemistry and the emission states of the CDs triggered by the alternative CO2/N2 introduction. We also find a similar luminescence change of the CDs upon alternative exposure to a humid vapor of CO2 and a mixture of NH3 and N2 at room temperature, allowing them to be used as a new class of optical materials for optical encoding.

Possible causes of the anomalous characteristics of autumn rain in western China in 2017

We analyzed the anomalous characteristics of autumn rain in western China (ARWC) (26.2–36° N, 101.9–111.8° E) in 2017 and the related large-scale atmospheric circulations based on new monitoring indicators published by the China Meteorological Administration in 2015 and the National Center for Environmental Prediction reanalysis data. We found that the characteristics of autumn rain in the southern (33–36° N, 101.9–111.8° E) and northern (26.2–33° N, 101.9–111.8° E) regions of the monitoring area were different. The onset date of autumn rain in the north (south) of the monitoring area in 2017 was 14 (16) days earlier than in normal years, which is in the 4th (4th) place since 1961. The end of the autumn rain was 5 days later (earlier) than in normal years. The autumn rain period was 54 (63) days long, 19 (11) days longer than in normal years. The autumn rainfall in the north (south) of the monitoring area was 234.1 (322.2) mm, 72.6% (74.4%) higher than that in normal years. The amount of autumn rain in the southern region is in the second place since 1965. The cause of this significantly early onset of the ARWC in 2017 was the advanced transition of the East Asian atmospheric circulation system from a summer pattern to a winter pattern. The westerly jet in the upper troposphere appeared about 10 days earlier than in normal years. The meridional circulation of a west-high and east-low pattern was observed in the mid- and lower troposphere in the mid- and high latitudes of Eurasia. This circulation configuration resulted in an early onset of the ARWC. As a result of the influence of the persistent warming of the Indian Ocean basin-wide mode from spring to summer, the west Pacific subtropical high was extremely strong (the second strongest since 1981) and its westernmost point was greatly extended to the west (the second greatest extension since 1981) during the autumn rain period. The intensity of the moisture flux from the southwest of the western Pacific subtropical high was stronger than usual and the low trough of Lake Baikal was also strong. Cold air from the north and the abundant warm, humid water vapor from the south converged in western China, resulting in more precipitation during the autumn rain period.

Moist Entropy and Water Isotopologues in a Zonal Overturning Circulation Framework of the Madden‐Julian Oscillation

AbstractThe Madden‐Julian oscillation (MJO) is the principal source of tropical intraseasonal variability, yet challenges remain to accurately simulate its observed convective behavior and eastward propagation. There is specific need for evaluating the role of water within the MJO, including evaporation, vertical transport, precipitation, and latent heating of the coupled atmosphere‐ocean system. Hydrogen isotope ratios are particularly useful for investigating these aspects of the water cycle. This study complements previous characterization of MJO joint distributions for water vapor and isotopologue concentrations (δD) with consideration of moist entropy in the tropical zonal overturning circulation framework of the MJO. The goals are to distinguish the roles of convective and large‐scale dynamic processes through the life cycle of the MJO and identify shortcomings for modeling MJO humidity, clouds, and convection. From MJO composite analyses, wet equivalent potential temperature (θq) anomalies are largest at 500 hPa and tilt westward with altitude. A positive θq anomaly co‐occurs with the precipitation maxima, and negative θq anomalies co‐occur with subsidence both trailing and leading the convective center. Out of phase with θq, δD anomalies are positive east and negative west of the convective center, coherent with the regional zonal overturning stream function. These results point to a decoupling in the MJO between midtroposphere water vapor, which is tied to convective processes, and the isotopologue ratios, which are tied to the large‐scale circulation. A conceptual model is presented to describe the physical processes that explain the MJO life‐cycle for joint distributions of humidity (q) and water vapor δD.

Water vapor transmission and water resistant: opposite but may coexist

Abstract Water vapor transmission (WVT) and water resistance (WR) are two important properties of functional textile for thermo-physiological comfort to the human body. Water vapor transmitting ability will maximize the comfort level of the human body when the body is in active mode, and water resistant textile will protect our body from rain. In this study, we propose a laminated fabric with both water resistant and water vapor transmission property. As we found that, this kind of laminated fabric have good mechanical property. Our synthesized segmented polyurethane membrane and its laminated fabric has low water vapor transmitting ability at low temperature or low relative humidity and high water vapor transmitting ability at high temperature or high relative humidity.

New Cloud Detection Index (CDI) for Forecasting the Extreme Rain Events

The water vapor content and clouds play a very significant role in atmospheric conditions. This paper is derived from the new cloud detection index (CDI) which is useful to forecast extreme weather events like heavy or extreme rain. The CDI is retrieved using two crucial elements of cloud formation, the critical humidity and critical water vapor. The cloud thickness is determined by using CDI for a radiosonde site (VABB) located in Mumbai, the western part of India. The obtained results are compared with the cloud thickness required for extreme rain. The outcome of the comparison is discussed in this paper. The cloud detection index is also useful in establishing the atmospheric stability along with another four atmospheric stability indices.

Assessing the Pattern Differences between Satellite-Observed Upper Tropospheric Humidity and Total Column Water Vapor during Major El Niño Events

As part of the activities for the Global Energy and Water Exchanges (GEWEX) water vapor assessment project, the consistency of satellite-observed upper tropospheric humidity (UTH) and total column water vapor (TCWV) is examined. The examination is focused on their respective patterns during major El Niño events. The analysis shows that the two datasets, consisting of one measurement of vertically averaged relative humidity in the upper troposphere and one of absolute water vapor integrated over the atmospheric vertical column with dominant contribution from the lower troposphere, are consistent over the equatorial central–eastern Pacific, both showing increases of water vapor during major El Niño events as expected. However, the magnitude of drying in the TCWV field over the western Pacific is much weaker than that of moistening over the central–eastern Pacific, while the UTH field exhibits equivalent magnitude of drying and moistening. Furthermore, the drying in the UTH field covers larger areas in the tropics. The difference in their patterns results in an opposite phase in the time series during a major El Niño event when a tropical average is taken. Both UTH and TCWV are closely correlated with major climate indices. However, they have significantly different lag correlations with the Niño 3.4 index in both the sign (positive or negative) and lag time over tropical oceans.

Management Implications of Snowpack Sensitivity to Temperature and Atmospheric Moisture Changes in Yosemite National Park, CA

AbstractIn order to investigate snowpack sensitivity to temperature increases and end‐member atmospheric moisture conditions, we applied a well‐constrained energy‐ and mass‐balance snow model across the full elevation range of seasonal snowpack using forcing data from recent wet and dry years. Humidity scenarios examined were constant relative humidity (high) and constant vapor pressure between storms (low). With minimum calibration, model results captured the observed magnitude and timing of snowmelt. April 1 snow water equivalent (SWE) losses of 38%, 73%, and 90% with temperature increases of 2, 4, and 6°C in a dry year centered on areas of greatest SWE accumulation. Each 2°C increment of warming also resulted in seasonal snowline moving upslope by 300 m. The zone of maximum melt was compressed upward 100–500 m with 6°C warming, with the range reflecting differences in basin hypsometry. Melt contribution by elevations below 2,000 m disappeared with 4°C warming. The constant‐relative‐humidity scenario resulted in 0–100 mm less snowpack in late spring vs. the constant‐vapor‐pressure scenario in a wet year, a difference driven by increased thermal radiation (+1.2 W/m2) and turbulent energy fluxes (+1.2 W/m2) to the snowpack for the constant‐relative‐humidity case. Loss of snowpack storage and potential increases in forest evapotranspiration due to warming will result in a substantial shift in forest water balance and present major challenges to land management in this mountainous region.

The functions of soil water and heat transfer to the environment and associated response mechanisms under different snow cover conditions

This study investigates the response mechanisms between soil water-heat transfer and environmental factors during freeze-thaw periods and establishes soil water-heat transfer functions in a cold region. Based on field-measured values of soil temperature and liquid-phase water content collected at an automatic weather station in the black soil area of the Songnen plain, the influence of the cumulative negative temperature on the soil freezing depth was analyzed under different snow cover conditions. A gray correlation analysis method was used to screen the environmental factors and determine those with the most influence on changes in soil water-heat transfer processes. Then, soil water-heat transfer functions were established between the selected environmental factors and soil temperature, the liquid-phase soil water content. The results showed that during the freezing and thawing period, snow cover hindered the effects of the cumulative temperature on the thickness of the frozen soil layer. Additionally, the time of occurrence of the maximum freezing depth under natural snow (NS), compacted snow (CS) and thickened snow (TS) treatments was delayed 7, 12 and 20 days, respectively, compared with that under bare land (BL). The correlation between atmospheric temperature, total radiation and soil temperature was relatively high, and this effect decreased with the increasing of snow cover. The main driving factors of variations in the liquid-phase water content were ambient humidity and saturated vapor pressure, and the effects of these factors decreased with increasing soil depth and snow cover thickness, similarly. In the active frozen layer, the correlation coefficients of the soil water-heat transfer functions were relatively high, and the function model can be tested by the significance (P < 0.05) test. However, the R2 values of functions below the active layer were relatively low, and the soil water-heat transfer in the area below the active layer was less affected by the environment. This study reveals the characteristics of energy transfer and mass transfer in a composite system of atmospheric factors and frozen soil under snow cover conditions. It provides a reference for accurate forecasting and the efficient utilization of soil water and heat resources in cold and arid regions.

Water dissipation mechanism of residential and office buildings in urban areas

Indoor humidity directly impacts the health of indoor populations. In arid and semi-arid cities, the buildings indoor humidity is typically higher than outdoors, and the presence of water vapor results from water dissipation inside the buildings. Few studies have explored indoor humidity features and vapor distribution or evaluated water dissipation inside buildings. This study examined temperature and relative humidity (RH) changes in typical residential and office buildings. The results indicate a relatively stable temperature with vary range of ±1°C and a fluctuation RH trend which is similarly to that of water use. We proposed the concept of building water dissipation to describe the transformation of liquid water into gaseous water during water consumption and to develop a building water dissipation model that involves two main parameters: indoor population and total floor area. The simulated values were verified by measuring water consumption and water drainage, and the resulting simulation errors were lower for residential than for office buildings. The results indicate that bathroom vapor accounts for 70% of water dissipation in residential buildings. We conclude that indoor humidity was largely a result of water dissipation indoors, and building water dissipation should be considered in urban hydrological cycles.

Humidity-responsive nanocomposite of gold nanoparticles and polyacrylamide brushes grafted on Ag film: synthesis and application as plasmonic nanosensor

A general stepwise strategy for the preparation of new humidity-responsive plasmonic nanosensor was described for the first time, based on Ag film functionalization by polyacrylamide (PAAM) brushes via surface-initiated atom transfer radical polymerization (SI-ATRP) method and then assembled with gold nanoparticles (Au NPs). We designed by this way a new plasmonic device made of Au NPs embedded in a humid vapor responsive polymer layer on Ag film and extensively characterized by surface-enhanced Raman scattering (SERS). When the relative humidity (RH) is above 50%, the number of plasmonic hotspots decreases, causing SERS signal reduced noticeably, for the volume expansion of PAAM brushes varied the nano-gap between closely spaced Au NPs, and between Au NPs and Ag film. The reversible optical properties of the prepared nanocomposite tuned by RH were probed through SERS using 4-mercaptopyridine (4-Mpy) as a molecular probe, and the decrease of the RH reversibly induces a significant enhancement of the 4-Mpy SERS signal. By means of the high reversibility, the RH responsive nanocomposite developed in this paper provides a dynamic SERS platform and can be applied as plasmonic nanosensor which is proved to be stable for at least two months.