Report on Sensing Concept for Counting Nanoparticle Suspended in Water

Introduction of Sensing Concept for Counting Nanoparticle Suspended in Water

Nanoparticle suspension in the liquid like water is very significant and unique research where their potential used is very advanced in the coolant applications.  Thermal conductivity of the water which could also increase through the solid particulates by the greater thermal conductivity through the parent liquid which is also maintained the suspension. The applications of the heat transfer where the suspension must be stable as well as it avoids the degradation and sediment during use (Chung, et al, 2009). There is the following method to fix the water, which had been polluted;

·         Filtration

·         UV disinfection

·         Chlorine disinfection’

·         Air stripper 

Filtration is used to remove the material from the water; as well as to remove the particulate the matter. Microorganism and the filtration devices along with the removal of particle changes with the type of the filter. The water surface is supplied by the lot of the suspended particle that also needed the pre-treatment for examples coagulation before the water filtering.

Literature Review of Sensing Concept for Counting Nanoparticle Suspended in Water

            As described by Wu & Islam (2007) in their study that the detection of low concentration of nanoparticles or pathogenic bioparticles on real-time is significant for the bioterrorism and deterring infectious diseases that is difficult to obtain for the current lab on a chip, sensitivity is achieved by processing sophisticated or culturing time consumingly often unfeasible under the conditions of the field. The sensor capability will be improved by real-time particle enrichment. The research study is providing the information in the situ nanoparticle that focuses on the approach integrated with beam identification. From the solution bulk on the electrodes for the sense of the particles, the AC electroosmosis is used to induce the particle convection for the fluid, therefore, increasing the local count of the nanoparticle. The ability of the detection of the cantilever may be highly improved as expected with preconcentrate use. Furthermore, coating the cantilevers can also obtain multiplexing detection along with several sensitive layers (Wu & Islam, 2007).

            Tuoriniemi, Cornelis, & Hassellöv (2012) explain the detection of the nanoparticles in the water and liquid with the information of their characteristics. Plasma mass spectrometry (spICPMS) were coupled by the detection capabilities of the single-particle inductively according to the number ad the size of concentrations which are evaluated for the silver nanoparticles case such as ca. 20-80 nm. Furthermore, it developed an iterative algorithm where the events of particle measurement were differentiated as the outliers from the constant dissolved ion signal if the intensity of measure was five times bigger than the standard deviation of a complete set of data. Although, the limiting multiple, incomplete events of particles, the optimal dwell time for the particles of 40-80 nm was 5 ms. The overlap of the dissolved signal, as well as the events of particles, mainly put the limit the smallest detectable nanoparticles having size ca. 20 nm, that enhances with the noise on both signals. The most reduced quantifiable number concentration is restricted by the relative recurrence of incorrectly distinguished molecule occasions, a restrain that can be decreased by obtaining more information focuses. At last, the potential of spICPMS for the natural discovery of nanoparticles is illustrated for a wastewater treatment plant refluent test (Tuoriniemi, Cornelis, & Hassellöv, 2012).

            As described by Dai, et al (2018), the emulsions have been applied in the subterranean on the larger scale enhanced the recovery process of oil, chemistry engineering field a well as the cosmetics engineering fields. Furthermore, it is also being focused by the current research interests on improving the emulsion stability through involving the colloidal or the surfactants materials. By introducing the silica nanoparticle (SNP), the main focus of this study is to increase in the stabilization of emulsion for the hydrophilized or the surface hydrophobized through adding OA-12 (dimethyl dodecyl amine) as well as to reveal the behaviour of such kinds of composites on the liquid to liquid interfaces dynamically. The nanoparticles typical dimensions are below the visible light’s diffraction limit and that’s why they are not in the range for the optical microscopy. The size measuring dependent Brownian motion of collective particles is involved by the most successful method in the range of the nanometer by changing the patterns interference with the time. Among the OA-12 and SNPs, the synergistic effect in the solution and the interface of water/oil were also studied through the measurement of emulsion viscoelastic rheology, interfacial rheology as well as the zeta potential. The researcher has also identified that the modified silica nanoparticles augmented interface of oil/water viscoelastic modulus, as well as at the same time of emulsions acquired the stability importantly for a long time. With the increase of the ratio of concentration among silica nanoparticle as well as OA-12, change type of emulsion, it induced the transformation phase. The molecules of OA-12 mounting adsorption on SNPs induce the inversions as suggested that can easily change the balance of hydrophilic-lipophilic of the particle surfaces (Dai, et al., 2018).

            Jain & Pradeep (2005) stated and explain in their study that the overnight exposure of foams can coat the silver nanoparticles on the common polyurethane (PU) foams by to nanoparticles solutions. Furthermore, the uniformly coated PU foam is yielded by the air drying and repeated washing that may be utilized as the filter for the drinking water where the contamination of bacteria of the water surface is risky for the human health. Nanoparticles are steady on the froth and are not washed away by water. Morphology of the froth was held after covering. The nanoparticle restricting is because it cooperates with the nitrogen molecule of the PU. Furthermore, it developed an iterative algorithm where the events of particle measurement were differentiated as the outliers from the constant dissolved ion signal if the intensity of measure was five times bigger than the standard deviation of a complete set of data. Online tests were led with a prototypical water channel. At a stream pace of 0.5 L/min, in which contact time was of the request for a second, the yield check of Escherichia coli was nil when the info water had a bacterial heap of 105 colony‐forming units (CFU) per mL. In the last, the large implications may also be had by the technology to developing countries as its effectiveness as well as combine with low cost in its applications (Jain & Pradeep, 2005).

            As stated, and explained by Park, Park, Lee, & Cho (2009), they developed a very effective aerosolization method for the real-time combine with the technique of membrane filtration to identify the number as well as the size of dissolved and suspended colloid nanoparticles the water. MF, UF or NF membranes treated feed water after and before, and the feed water was also dried as well as aerosolized in situ, and size and the number of the particles were determined in the real-time. Furthermore, to analyze and evaluate the current method, technique or approach performance, it used the NaC1 nanoparticles along with the varying solute concentration, CaCO3 as well as Humic acid, and the standard particles with determining number and size. It developed an iterative algorithm where the events of particle measurement were differentiated as the outliers from the constant dissolved ion signal if the intensity of measure was five times bigger than the standard deviation of the complete set of data. We additionally estimated size and number of colloidal nanoparticles in wastewater gushing, waterway water, and seawater. We found that there exists a critical number of nanoparticles staying significantly after UF and NF filtration, proposing that broke down nanoparticles that made due by UF and NF filtration may influence the fouling in RO layers in the desalination procedure. The broke up nanoparticles are characterized here as those that are initially not in molecule stage in feed water yet that can accelerate close to the films by crystallization or focus polarization as molecule stage. It achieved the suspended as well as separating dissolved nanoparticles in the water along with leading and the current methods for the determination of their relative contribution into the water for feed. The division of broken up nanoparticles in seawater that survived through NF filtration in add up to molecule number is 66% whereas that in-stream water is 44%. TEM/EDS investigation confirmed that a noteworthy sum of broken up nanoparticles survived through UF and NF filtration, which particular sorts of broken-down nanoparticles exist in stream water and seawater. Into the four types, it classifies the dissolved nanoparticles in the seawater which are: carbon-mineral rich spherical particles (C-Cu-Ca-O-Si-Mg), the irregular particles like carbon-mineral rich (Ca-O-C-Mg-S-Cl-Si), the cubic particles of Na-containing as well as the spherical particles of rich carbon (Park, Park, Lee, & Cho, 2009).

Detection of Nanoparticles and Specific properties

            The nanoparticles detection as well as their specific properties measurement linked and essential for two distinguished reasons. To detect the nanoparticles and their particular properties, the methods are needed and measure their physicochemical properties in the media in which ecosystems and human have uncovered them such as water. To access the risk of nanoparticles, some methods are also available that support this study. For this purpose, the tools such as sensors are required in relevant medium including fluids and especially in the water.

            The second issue associates with the chemical or physical properties linked with the nanoparticles based on nanoparticles detection in the media. The nanoparticles properties range of potential relevance to the assessment of risk highlights the needs of the principles for the sensitive methods for detection. The nanoparticles typical dimensions are below the visible light’s diffraction limit and that’s why they are not in the range for the optical microscopy. The detection of the single chromophore is possible in the low concentration liquids like water, as well as the single chromophore detection is into the scanning near field optical microscopy feature of sub-wavelength can be analyzed. Furthermore, by the classic analytic methods for the macroscopic amounts of material, the nanoparticle’s chemical composition could be accessible. The individual nanoparticles chemical analysis in the dilute environment was impossible for a long time because of low mass.

Nanoparticles Detection in a liquid medium

            The nanoparticle direct detection in the liquid media such as water looks the same kind of physical obstacles as detected in gas media. The size measuring dependent Brownian motion of collective particles is involved by the most successful method in the range of the nanometer by changing the patterns interference with the time. Although, the lower detection limit of 3nm is reached by the commercially available instruments. By using different significant technique containing Raman scattering, resonant light scattering and the optical chromophore counting techniques, as well as the cross-section cuts and the microscopic precipitates analysis. To identify the compounds, it has used the very sensitive methods in the mass spectrometry, electrochemistry as well as Rutherford backscattering.

            There are several types of techniques present which are offline as well as complex sample preparation techniques. It is also possible to count the online low concentration particle through the use of magnetic nanoparticles as tracers, quantum dots or the fluorescent molecules. Although, the choice of chromophores and the nanoparticles put further limits on the system.

            To investigate the size, structure as well as the shape of the nanoparticle, the scanning Electron microscopy (SEM) method is used. It can also determine the chemical compositions when equipped with the Electron Dispersive Spectrometer. For the chemical analysis, the Xray microanalysis system is not always suitable because it can only perform the substance identification or detection on the level of the element as well as it cannot be quantified. Furthermore, it can also analyze the very high nanoparticle's vapour pressure to the strong vacuum system that required for the X-ray microanalysis.        It has been progressed by the related techniques and the SEM resolution below 10 nm because of the cold electron sources implementation in the latest instruments. Furthermore, the resolution of SEM has also been improved in the high-resolution transmission electron microscopy (HRTEM) approaches, or the Scanning transmission electron microscopy (STEM) that can be collected again for the highly powerful approaches analytically through the use of X-ray analysis and the electron probes analysis.  

Type of particles of Sensing Concept for Counting Nanoparticle Suspended in Water

The type of nanoparticles identified in this section which is classified on the basis of size, physical as well as chemical properties. The nanoparticles which are identified and discussed in the document are metal nanoparticles. These nanoparticles can also be synthesized by chemical method. In the chemical methods, reducing the metal ion precursor in the liquid through the chemical reducing agents, obtain the metal nanoparticles in to the water or liquid. These particles has also the ability to adsorb the tiny molecules as well as they also have the high energy of surface. The identified nanoparticles has also the applications in the areas of the research, imaging as well as detection of the biomolecules, the bioanalytical applications as well as into the environmental applications. For instance, it uses the gold nanoparticles for coating the sample before the evaluation in SEM. To increase the electronic stream, it is usually done, that can be very helpful in the analysis to obtain the images in high quality.

Method of detecting and Counting of Suspended Particle

            According to the study, the suspended particle in the water can be measured as well as calculated using a particles counter suspended in the water. Furthermore, the results of this experiment for counting the number of nanoparticles in water with that turbidity. According to the diagram given below, it removed the nephelometric turbidity in the same type of degree as the optimum suspended particles. The finer particles' dominating effect on the counting turbidity is also discussed in the study.

            The entire filtration process consists of different levels of removability of coarser particles. The ending of each cycle provides significant removability of the particles and ends at the turbidity levels. the rationalization can be done for the fall in the efficiency regarding the removal of coarser particles. The increasing deposit content of the bed result as fall in the bed porosity. On the contrary, the decreasing porosity leads to an increase in the flow rate between the grains and eventually the shear stress is increased. In case of going beyond the shear stress limit, the bed face sudden fall and removal of particles. Comparing the removal time limit, the coarser particles are removed earlier as compared to the finer particles. Hence considering the outcome of comparison and reports, the removal efficiency of the particles is of the size range of as to 25 micrometres is 4 hours and deteriorates of 15 to 25 micrometres is 6 hours. the difference in the removal efficiency appears only in the last hours. measuring the time efficiency of removing the particles enables to count the particles expected in the solution. the colloidal solution of nanoparticles becomes the turbid solution.

            Different methods are devised to calculate the number of nanoparticles in the water solution. the interaction between the electromagnetic field and nanoparticles are used for sensing the single nano photon limit of the digital resolution counting and detection through the absorption, intrinsic dielectric permittivity, and scattering. The size of the nanoparticles in water can be measured by several ways including electron beam microscopy, stimulated emission depletion microscopy (STED), confocal fluorescence microscopy, photo-activated localization microscopy, (PALM), super-resolution methods (SIM), stochastic optical reconstruction microscopy (STORM). These techniques are used to observe the presence, feature and size of the nanometer-scale objects. These approaches are capable to measure the size and image of the nanoparticles. Imaging the nanoparticles enable the counting within the field of view. The presence of nanoparticles on the perimeter of the WSG sensor is used based on the capability of scattering the light and light propagate in the reverse direction that case single initial WSG model. The process depends on the ability to resolve the wavelength shifts that range from 0.1 pm to several nanometers for the different combinations of modal volumes that generated broad interest with the variety of geometries such as spheres, disks, bottles, droplets, bubbles, and capillaries. The important factors in the accurate determination of the nanoparticle numbers are dependent on the molar concentration. The goal of analytical methods is to calculate the concentration based conditions under light absorption and direct sensing. The methods adopt different mechanisms and have limited certainties for the size of the nanoparticles.   

Figure 1 above illustrates the relationship between time and the number of particles in the solution in the filtration process. The graphical representation shows that the number of particles in the filtration process decreases based on the size of the particle.

Calculating Volume/ Size of Nanoparticle

            One to the most useful method is DLS that subsequently depends on the size and concentration of distribution of nanoparticles. In this method, the light intensity of scattering light is changed after being scattered from the nanoparticles. In the case of monodispersed nanoparticle solution, the intensity of the light scattered from the solution is directly proportional to the number of nanoparticles in the solution. the method is an efficient way to measure the number of particles by using DLS determination technique for the concentration of nanoparticles. The method is based on the photon count rate that indicates the possible number of nanoparticles in the solution. The photon count rate can be defined as the number of photons that are detected per second by using the DLS system. the unit of the detected number of photons per second by DLS is kilo counts per second (KCPS). In the condition of concentration range, the photon count rate is directly proportional to the intensity of the scattered light from the colloidal dispersions

Here, I define the intensity of scattered light, P is the photon count rate, and B is a constant. The intensity provides information about the number of particles that is the concentration and size of the particles based on the scattering conditions. In case the nanoparticles are small as compared to the Rayleigh scattering then the limitations of scattered light intensity induce impact on the outcomes of the measurements. Equation 2 is given below that measure the concertation of the nanoparticles in the solution (Shang & Gao, 2015).

In the above equation 2,  is the intensity of the incident light,  is the angle of light scattered, R is the distance between the particle and the point at which it is observed, m defines the refractive index ratio of the particles with the medium, d is the nanoparticle diameter, and C is the nanoparticle concentration in the fluid. The parameters  are used from the DLS instrument. Therefore, based on the recorded information, the equation reduces to equation 3,

Here the parameter  is the instrument coefficient, P is photon count rate that is proportional to the number of concentration of nanoparticles as C. the photon count rate and calibration curve both are used to measure the photon count rate and this method can be applied to several prerequisites. In the process, both solvent and nanoparticles are unknown samples and detection of each component is based on the effective refractive index m and size of nanoparticle as d in the photon. The second method is by using DLS instrument automatically optimize the attenuation factor. The actual rate is then defined based on calculated reported count rate and divided by the attenuation factor. In this process first, the colloidal solution is prepared, and a linear calibration curve is used between P and C. in some previous works, the results from the DLS measurement are consistent with the results of total atoms (Zucker, Ortenzio, & Boyes, 2015). The limitation of the method is mainly linked with the number of internal references and the DLS method cannot distinguish between two different particles. The ideal method of analysis is based on the unknown sample with the nanoparticle concentration. The standard method uses the refractive index. As the fundamental characteristics of nanoparticles are volume, concentration, and mass. The volume of the nanoparticle can be measured based on its dimensions. The dimension can be measured by using transmission electron microscopy (TEM) (Pastor, Long, Li, & Manoto, 2018).  The volume measurement is also based on the type and shape of the nanoparticle. Following equations 3, 4,5 and 6 provide formulism for the volume measurement.

In most of the cases, the density of nanoparticles is bulk density and mass calculation is assumed based on the mass of material from which the nanoparticles are made of. Table 1 below provides fundamental information about the density of the nanoparticles.

Table 1:Density of the nanoparticle with comparison to the bulk density

Use of Nanoparticles in Different Applications

            In the biomedical applications, nanoparticles are used for the imaging, biosensing, antimicrobial, and drug delivery process. In the environmental applications, nanoparticles were used for the bioremediation and the diverse containment of water treatment. Besides these applications, nanoparticles are used to produce clean energy. The semiconductor nanoparticles are used in electronic devices, photocatalysis, photo-optics, and water splitting applications (Jain & Pradeep, 2005).

Conclusion of Sensing Concept for Counting Nanoparticle Suspended in Water

            The primary concern of the present work was to measure accurately nanoparticle concentration. Different technologies are devised to measure the concentration of all nanoparticles with the size limitation of 1 nm, the simple setup and easy to operate is another feature of these methods. The capability to measure the concentration of nanoparticles is based on the physical properties such as extinction coefficient and scattering coefficient. The simple and accurate measurement of concentration, size, and volume of nanoparticles is helpful to transform the way from which nanoparticles are assessed, functionalized, and expand the impact of nanotechnology in the many fields such as catalysis, electronics, photonics, and medicine.

References of Sensing Concept for Counting Nanoparticle Suspended in Water

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Dai, C., Li, H., Zhao, M., Wu, Y., You, Q., Sun, Y., . . . Xu, K. (2018). Emulsion behavior control and stability study through decorating silica nano-particle with dimethyldodecylamine oxide at n-heptane/water interface. Chemical Engineering Science, 73-82.

Jain, P., & Pradeep, T. (2005). Potential of silver nanoparticle‐coated polyurethane foam as an antibacterial water filter. Biotechnology and Bioengineering.

Park, K., Park, J. Y., Lee, S., & Cho, J. (2009). Measurement of size and number of suspended and dissolved nanoparticles in water for evaluation of colloidal fouling in RO membranes. Desalination, 78-89.

Pastor, M. Á., Long, K. D., Li, N., & Manoto, S. L. (2018). Detection and Digital Resolution Counting of Nanoparticles with Optical Resonators and Applications in Biosensing. Conference paper, 01(02), 01-10.

Shang, J., & Gao, X. (2015). Nanoparticle Counting: Towards Accurate Determination of the Molar Concentration. Chem Soc Rev, 43(21), 7267-7278.

Tuoriniemi, J., Cornelis, G., & Hassellöv, M. (2012). Size discrimination and detection capabilities of single-particle ICPMS for environmental analysis of silver nanoparticles. Analytical chemistry, 3965-3972.

Wu, J., & Islam, N. (2007). A simple method to integrate in situ nano-particle focusing with cantilever detection. IEEE Sensors Journal, 957-958.

Zucker, R. M., Ortenzio, J. N., & Boyes, W. K. (2015). Characterization, detection, and counting of metal nanoparticles using flow cytometry. Cytometry, 89(02), 01-10.