Selective Preconcentration Research Articles

Novel water-compatible surface molecularly imprinted polymer microspheres based on boronate affinity and hydrophilic coating for efficient enrichment and separation of capecitabine from urine samples

A novel water-compatible surface molecularly imprinted polymer microspheres (SMIMs) based on boronate affinity and hydrophilic coating were developed for the specific recognition and extraction of capecitabine (CAP). The boronic acid-functionalized polymer microspheres (BPMs) were first prepared as the carrier through dispersion polymerization using methyl methacrylate, ethylene glycol dimethacrylate, and 4-vinylphenylboronic acid as the polymerization monomers. Subsequently, the CAP template was immobilized onto the surface of the BPMs by virtue of boronate affinity. Finally, a thin and adherent imprinting layer was coated onto the surface of the BPMs via in-water self-polymerization of dopamine (DA) and polyethyleneimine (PEI). The resulting SMIMs exhibited strong hydrophilicity, high adsorption capacity (151.52 μmol/g) and a great imprinting factor (5.99) for CAP in aqueous media. The adsorption behavior of CAP onto the SMIMs was in good agreement with the Langmuir model and the pseudo-second-order equation. Selective adsorption indicated that the SMIMs exhibited a higher specific recognition for CAP compared to other structural analogs. In addition, the SMIMs showed excellent reproducibility and reusability, and could be utilized as anadsorbent in solid-phase extraction (SPE) for the selective pre-concentration, purification, and detection of trace amounts of CAP in spiked urine samples in combination with HPLC. The elution recovery of CAP for the various spiked levels ranged from 91.7 % to 104.9 %, with a relative standard deviation (RSD) of less than 5.8 % (n = 3).

Recent progress of covalent organic frameworks in high selective separation of radionuclides

The utilization of nuclear energy power and nuclear weapon tests not only releases large amounts of radionuclides into environment, but also needs 235U as nuclear fuel for nuclear energy generation. Covalent organic frameworks (COFs) have the advantages of tunable porous structures, adjustable active sites and enough special functional groups, which assure the high selective preconcentration of target radionuclides from complex solutions. In this perspective, the selective extraction of radionuclides (U(VI) as representative cationic ion, Tc(VII) as representative anionic ion, I2 as gaseous nuclide and other nuclides) by COFs through sorption, and photocatalytic strategies are described, and the results show the high efficiency of COFs in target radionuclides removal. The perspective and challenges for the real applications of COFs in future are discussed in the end.Graphical

A Stable and Sensitive Engineering Bacterial Sensor via Physical Biocontainment and Two-Stage Signal Amplification.

Although engineering bacterial sensors have outstanding advantages in reflecting the actual bioavailability and continuous monitoring of pollutants, the potential escape risk of engineering microorganisms and lower detection sensitivity have always been one of the biggest challenges limiting their wider application. In this study, a core-shell hydrogel bead with functionalized silica as the core and alginate-polyacrylamide as the shell have been developed not only to realize zero escape of engineered bacteria but also to maintain cell activity in harsh environments, such as extremely acidic/alkaline pH, high salt concentration, and strong pressure. Particularly, after combining the selective preconcentration toward pollutants by functionalized core and the positive feedback signal amplification of engineering bacteria, biosensors have realized two-stage signal amplification, significantly improving the detection sensitivity and reducing the detection limit. In addition, this strategy was actually applied to the detection of As(III) and As(V) coexisting in environmental samples, and the detection sensitivity was increased by 3.23 and 4.39 times compared to sensors without signal amplification strategy, respectively, and the detection limits were as low as 0.39 and 0.86 ppb, respectively.

Paper-based biomimetic test-strip for CA15-3 with coloured readout

The combination of molecularly-imprinted polymers (MIPs) on paper substrates for capturing a cancer antigen 15–3 (CA15-3) with the traditional coloured transduction scheme of enzyme-linked immunosorbent assay (ELISA) using 3,3′,5,5′-tetramethylbenzidine (TMB), horseradish peroxidase (HRP) and H2O2 is presented here for the first time.Here, the paper surface was modified with a silane derivative containing an amine function that allows subsequent binding of 3-aminophenylboronic acid (3-APBA). The target protein, CA15-3, was then bound via the boronic groups of APBA. The empty space around CA15-3 was filled by polymerization of dopamine. Finally, the CA15-3 template was removed by breaking the imine function to create vacant sites for which CA15-3 has a high affinity. Binding of CA15-3 was detected by oxidation of TMB substrate by HRP in the presence of H2O2.The results showed that the MIP was able to selectively recognize CA15-3 within 3–500 U mL−1, even in complex samples. Quantitative data were extracted by analysing the colour coordinates of images captured with a smartphone using ImageJ. This selective behaviour was confirmed by comparison with a control material (non– polymer, NIP).Overall, the described approach has advantages over conventional ELISA, namely low cost and high stability, which is due to the use of MIP as a trapping element acting as a selective pre-concentration point of CA15-3. To our knowledge, this is the first biomimetic ELISA (B-ELISA) on paper substrate used for macromolecules such as proteins. We believe that this approach has the potential to be applied to other protein disease biomarkers, making it a suitable tool for screening glycoproteins at the point-of-care.

Homogeneous Electrochemical Aptasensor for Sensitive Detection of Zearalenone Using Nanocomposite Probe and Silica Nanochannel Film.

Developing rapid and efficient analytical methods is of great importance for food safety Herein, we present a novel homogeneous electrochemical aptasensor for ultrasensitive quantitative determination of zearalenone (ZEN) based on a nanocomposite probe and silica nanochannel film. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and UV-Vis characterization techniques confirm that graphene oxide (GO) bears an aromatic conjugated structure, along with hydroxyl and carboxyl groups, facilitating the subsequent adsorption of cationic redox hexa-ammine-ruthenium (III) (Ru(NH3)63+) and anionic ZEN aptamer, to form a Ru(NH3)63+-ZEN aptamer-GO nanocomposite probe in a homogeneous solution. Vertically-ordered mesoporous silica films (VMSF) bearing silanol groups can be simply grown on the solid indium tin oxide (ITO) electrode surface and enable the selective preconcentration of Ru(NH3)63+, eventually leading to signal amplification. Since the detachment of Ru(NH3)63+ from the GO surface by the recognized ZEN aptamer in the presence of ZEN, more free Ru(NH3)63+ is released in solution and produces enhanced redox signals at the VMSF modified ITO electrode, allowing quantitative detection of ZEN. On the basis of the above sensing strategy, the proposed homogeneity, due to the assistance of graphene, as well as of the signal amplification and anti-fouling effects of VMSF, accurate analysis of ZEN can be realized in maize and Chinese chestnut samples.

DCas9-Mediated PCR-Free Detection of Oncogenic Mutation by Nonequilibrium Nanoelectrokinetic Selective Preconcentration.

Cutting-edge nanoelectrokinetic technology in this work provides a breakthrough for the present clinical demands of molecular diagnosis to detect a trace amount of oncogenic mutation of DNA in a short time without an erroneous PCR procedure. In this work, we combined the sequence-specific labeling scheme of CRISPR/dCas9 and ion concentration polarization (ICP) mechanism to separately preconcentrate target DNA molecules for rapid detection. Using the mobility shift caused by dCas9's specific binding to the mutant, the mutated DNA and normal DNA were distinguished in the microchip. Based on this technique, we successfully demonstrated the dCas9-mediated 1-min detection of single base substitution (SBS) in EGFR DNA, a carcinogenesis indicator. Moreover, the presence/absence of target DNA was identified at a glance like a commercial pregnancy test kit (two lines for positive and one line for negative) by the distinct preconcentration mechanisms of ICP, even at the 0.1% concentration of the target mutant.

Recent Progress of Molecularly Imprinted Optical Sensors

Molecularly imprinted polymers (MIPs) have been widely utilized in the field of sensing due to their specific and high affinity towards target molecules. Combining the selective preconcentration capability of MIPs and the rapid quantitation merit of optical analytical techniques, MIP optical sensors have been applied to the analysis of various kinds of samples and have received considerable attention in recent years. In this review, we overviewed the progress of MIP sensors in combination with various optical detection methods, including fluorescence, surface plasmon resonance, Raman scattering, and chemiluminescence. The construction, characterization, working principle, and application of four kinds of MIP optical sensors are covered in detail. Finally, the opportunities and challenges currently encountered by MIP optical sensors are summarized.

Rapid quantification of 2,4-dichlorophenol in river water samples using molecularly imprinted polymers coupled to ambient plasma mass spectrometry

Rapid quantification of environmental pollutants is important for water quality control and environmental monitoring. In this work, we report the development of molecularly imprinted polymers (MIPs) obtained from poly(methyl vinyl ether-alt-maleic acid) polymer. The synthesized materials were used for selective preconcentration of 2,4-dichlorophenol, a priority pollutant which creates a threat to public health. The structure of poly(methyl vinyl ether-alt-maleic acid) was functionalized with 4-aminomethylpyridine (4-AMP) to incorporate pyridine groups presumably responsible for increased affinity towards 2,4-dichlorophenol. The synthesis was performed with different degree (10%, 20% and 30%) of 4-AMP functionalization to investigate the influence of pyridine group content on the final MIPs properties. The molecular imprinting process was conducted by amidation of polymers’ anhydride groups with diethylenetriamine. Moreover, the experimental data indicated that maximum adsorption capacity was observed for the highest 4-AMP functionalization degree. Similarly, MIPs with the highest 4-AMP content proved to possess the highest selectivity towards the analyte. Finally, the functionalized MIPs were used to quantify 2,4-dichlorophenol by their direct introduction into a specially designed ambient mass spectrometry setup. The detection limits were improved significantly over the ones measured for pure analyte solution. The proposed analytical technique was used to quantify 2,4-dichlorophenol in river water and wastewater samples. Good recovery results were obtained, which proves that the method can be used for analysis of complex real-life samples.

Imidazolium-Modified Silica Gel for Highly Selective Preconcentration of Ag(I) from the Nitric Acid Medium

The ion-exchange behavior of an organomineral material with an imidazolium (1-methyl-3-(prop-2-yn-1-yl)-1H-imidazol-3-ium bromide)-modified silica gel was studied for the extraction of Ag(I) from nitric acid media. The extraction from multicomponent systems containing Fe(III), Co(II), Ni(II), Cu(II), Pb(II), and Mn(II) in 100- and 1000-fold molar excesses with respect to Ag(I) was shown to occur with high selectivity. Based on the data of X-ray diffraction and X-ray fluorescence spectroscopy for samples of modified silica gel, a mixed ion exchange–adsorption mechanism for the extraction of Ag(I) was proposed. The effect of the phase contact time and the concentration of nitric acid on the distribution coefficient of Ag(I) was studied. The selectivity factors of the extraction of Ag(I) from multicomponent systems containing foreign cations in 100- and 1000-fold molar excesses under steady-state and dynamic concentration conditions were calculated.

Escherichia coli Enumeration in a Capillary-Driven Microfluidic Chip with SERS.

Pathogen detection is still a challenging issue for public health, especially in food products. A selective preconcentration step is also necessary if the target pathogen concentration is very low or if the sample volume is limited in the analysis. Plate counting (24–48 h) methods should be replaced by novel biosensor systems as an alternative reliable pathogen detection technique. The usage of a capillary-driven microfluidic chip is an alternative method for pathogen detection, with the combination of surface-enhanced Raman scattering (SERS) measurements. Here, we constructed microchambers with capillary microchannels to provide nanoparticle–pathogen transportation from one chamber to the other. Escherichia coli (E. coli) was selected as a model pathogen and specific antibody-modified magnetic nanoparticles (MNPs) as a capture probe in a complex milk matrix. MNPs that captured E. coli were transferred in a capillary-driven microfluidic chip consisting of four chambers, and 4-aminothiophenol (4-ATP)-labelled gold nanorods (Au NRs) were used as the Raman probe in the capillary-driven microfluidic chip. The MNPs provided immunomagnetic (IMS) separation and preconcentration of analytes from the sample matrix and then, 4-ATP-labelled Au NRs provided an SERS response by forming sandwich immunoassay structures in the last chamber of the capillary-driven microfluidic chip. The developed SERS-based method could detect 101–107 cfu/mL of E. coli with the total analysis time of less than 60 min. Selectivity of the developed method was also tested by using Salmonella enteritidis (S. enteritidis) and Staphylococcus aureus (S. aureus) as analytes, and very weak signals were observed.

Vortex-assisted dispersive micro-solid phase extraction based on nanostructured imprinted polymer: A comparison study between spectrophotometric and solution scanometric techniques

In the present work, methyl red molecularly imprinted polymeric (MR-MIP) nanostructure was synthesized using the precipitation polymerizations for the separation of MR dye from aqueous media. The as-prepared MIP was characterized using colorimetry, infrared (IR) spectroscopy, and scanning electron microscopy (SEM). In addition, vortex-assisted dispersive micro-solid phase extraction (VAD-µSPE) based on MIP nanostructure was accomplished as a simple and efficient method for selective preconcentration of low amounts of MR from aqueous solutions. The effects of important parameters such as pH, adsorbent dose, eluent volume, and vortex adsorption–desorption time on the extraction efficiency were investigated. Two techniques including UV–Vis absorption spectroscopy and solution scanometry were applied for the analysis of MR content, comparatively. In spectrophotometric determination, the highest recovery was observed at pH 3.5 after 5 and 3 min of vortex time in the adsorption and desorption steps. The preconcentration factor of 75 and a wide linear concentration range (0.010 and 2.0 mg.L−1; R2 = 0.996) and low detection limit (LOD = 5.0 µg.L−1) with an acceptable precision (RSD = 3.4 %) was observed, too. Under optimum conditions in scanometric determination, a high preconcentration factor (i.e. 500) and similar linearity (0.010–2.0 mg.L−1; R2 = 0.989) and a low LOD of 3.1 µg.L−1, with the relative standard deviation of 1.4% was observed. Both techniques were used for MR recovery from various aqueous samples, successfully.

Synthesis, characterization and application of a zirconium-based MOF-808 functionalized with isonicotinic acid for fast and efficient solid phase extraction of uranium(VI) from wastewater prior to its spectrophotometric determination

BackgroundA zirconium-based metal-organic framework (Zr-MOF), named MOF-808, was synthesized and fully characterized by solvo-thermal method and functionalized by isonicotinic acid and employed as an efficient adsorbent for selective extraction and preconcentration of uranyl ions from water and waste water samples in a batch solid phase extraction.ResultsParameters affecting extraction such as volume and pH of the sample solution, the amount of sorbent, type and volume of eluting solvent, and adsorption and desorption times were investigated and optimized. Under the optimized conditions, high extraction efficiency was observed with a limit of detection of 0.9 µg L− 1 for uranyl ions and relative standard deviations were found to be better than 2.1% in the range of 0.07–1000 µg L− 1.ConclusionsThese results indicated that the above procedure is fast, inexpensive, effective, reliable, applicable and organic solvent-free and showed the highly performance and stability of the Zr-MOF in SPE based analytical techniques.

Determination of Cr (III) and Cr (VI) In Water by Selective Separation and Preconcentration on Hybrid Resin

Abstract Simple and rapid method has been developed for separation, preconcentration and determination of Cr(III) and Cr(VI) species in water by using selective hybrid R-Cu-(OH)2 resin (HCR). The effect of pH value on the adsorbed of Cr(VI) was investigated, Cr(VI) species can be retained on the HCR and eluted by 1.0 M of NaOH solution completely while Cr(III) can not adsorbed on HCR. Chromium species before and after separation process were measured with 1-5-diphenylcarbazide by using spectrophotometer. The results showed that the capacity of HCR on adsorbed of Cr(VI) was 3.43 mg g-1. The concentration of Cr(V) determined by different between total Cr and Cr(III). The recovery of the determination of Cr(III) and Cr(VI) were ( 93.0 % to 101% ) and (93.6 % to 105 % ) respectively , while the RSD were ( 0.99% -6.18% ) and ( 1.63%-7.3% ) for Cr(III) and Cr(VI) respectively.

Application of flow injection analysis-solid phase extraction based on ion-pair formation for selective preconcentration of trace amount of anti-HIV drug

In this study, a flow injection analysis (FIA) system combined with solid phase extraction (SPE) was designed for preconcentration and selective extraction of an HIV anti-virus drug (i.e. Nevirapine (NVP)). Molecularly imprinted polymer (MIP) nanostructures were used as the selective adsorbent in the extraction column. The synthesis of MIP was carried out, using methacrylic acid (MAA) as the functional monomer, ethyleneglycoldimetacrylate (EGDMA) as the cross-linking agent in methanol/acetonitrile as porogen solvent. Scanning electron microscopy (SEM) and differential thermal analysis (DTA) were used for the characterization of the as-synthesized NVP-MIP. In the SPE-FIA procedure, after analyte loading, the eluted NVP drug was treated with fast green (FCF) as a colorimetric reagent. After the formation of colored ion-pair between NVP and FCF in an acidic media, the quantitative determination was performed spectrophotometrically at 620 nm. The influence of experimental parameters on the NVP extraction, including adsorption and desorption flow rate, MIP amount, sampling time, and elution condition were studied and optimized. For the present method, two linear concentration ranges (0.0010–0.10 mg L-1 and 0.10–80 mg L-1), a low detection limit of 0.0005 mg L-1, and an acceptable preconcentration factor of 100 was obtained in optimum conditions. Meanwhile, a selective binding affinity of NVP toward MIP sorbent was observed against other drugs, in the selectivity study. Moreover, the applicability of the designed method was confirmed by successfully uptaking NVP from human urine real samples and artificial aqueous samples.

Preparation of Fe3O4@SW-MIL-101-NH2 for selective pre-concentration of chlorogenic acid metabolites in rat plasma, urine, and feces samples

An innovative sandwich-structural Fe-based metal-organic framework magnetic material (Fe3O4@SW-MIL-101-NH2) was fabricated using a facile solvothermal method. The characteristic properties of the material were investigated by field emission scanning electron microscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, vibrating sample magnetometry, and Brunauer-Emmett-Teller measurements. Fe3O4@SW-MIL-101-NH2 is associated with advantages, such as robust magnetic properties, high specific surface area, and satisfactory storage stability, as well as good selective recognition ability for chlorogenic acid (CA) and its metabolites via chelation, hydrogen bonding, and π-interaction. The results of the static adsorption experiment indicated that Fe3O4@SW-MIL-101-NH2 possessed a high adsorption capacity toward CA and its isomers, cryptochlorogenic acid (CCA) and neochlorogenic acid (NCA), and the adsorption behaviors were fitted using the Langmuir adsorption isotherm model. Then, a strategy using magnetic solid-phase extraction (MSPE) and ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF MS/MS) was developed and successfully employed for the selective pre-concentration and rapid identification of CA metabolites in rat plasma, urine, and feces samples. This work presents a prospective strategy for the synthesis of magnetic adsorbents and the high-efficiency pretreatment of CA metabolites.

Nickel contamination analysis at cost-effective silver printed paper-based electrodes based on carbon black dimethylglyoxime ink as electrode modifier

Electrochemical detection of metal cations at paper-based sensors has been suggested as an attractive alternative to current spectroscopic and chromatographic detection techniques due to the ease of fabrication, disposable nature, and low cost. Herein, a novel carbon black (CB), dimethylglyoxime (DMG) ink is designed as an electrode modifier in conjunction with 3-electrode inkjet-printed paper substrates for use in the adsorptive stripping voltammetric electroanalysis of nickel cations in water samples. The developed method provides a novel, low-cost, rapid, and portable adsorptive stripping detection approach towards metal analysis in the absence of the commonly used toxic metallic films. The study demonstrated a novel approach to nickel detection at paper-based sensors and builds on previous work in the field of paper-based metal analysis by limiting the use of toxic metal films. The device sensitivity is improved by increasing the active surface area, electron transfer kinetics, and catalytic effects associated with non-conductive dimethylglyoxime films through CB nanoparticles for the first time and confirmed by electroanalysis. The first use of the CB-DMG ink allows for the selective preconcentration of analyte at the electrode surface without the use of toxic Mercury or Bismuth metallic films. Compared to similarly reported paper-based sensors, improved limits of detection (48 µg L-1), selectivity, and intermetallic interferences were achieved. The method was applied to the detection of nickel in water samples well below World Health Organization (WHO) standards.

Protein Corona-Induced Extraction after Fe3+/H2o2 Degradation for Selective Preconcentration of Silver Sulphide Nanoparticles from Environmental Waters

Protein Corona-Induced Extraction after Fe3+/H2o2 Degradation for Selective Preconcentration of Silver Sulphide Nanoparticles from Environmental Waters

Development of a novel porous cobalt, phosphorus and nitrogen co-doped carbonaceous coating by phosphiding ZIF-67 grown on nitinol fiber for selective solid-phase microextraction of polycyclic aromatic hydrocarbons from water samples.

The nature and fabrication of the fiber coatings with good adsorption capacity and selectivity play a decisive role in solid-phase microextraction (SPME). In this work, a facile strategy was proposed to fabricate a cobalt, phosphorus and nitrogen co-doped carbonaceous (Co-P-NC) coating on superelastic nitinol (NiTi) substrate as a binder-free fiber for SPME. In particular, direct electrochemical in situ growth of ZIF-67 crystals served as the N-containing carbon precursor and sacrificial template for subsequent controllable conversion of ZIF-67 into a novel porous Co-P-NC coating on the NiTi wire substrate via a phosphiding process in a N2 atmosphere. The obtained NiTi wire with the Co-P-NC coating (NiTi@Co-P-NC) was employed to investigate the adsorption of some representative aromatic analytes in water samples for the first time coupling with high-performance liquid chromatography with UV detection (HPLC/UV). The results proved that the resulting fiber showed superior adsorption selectivity for polycyclic aromatic hydrocarbons (PAHs). Therefore, the key parameters were further examined for the adsorption and preconcentration of PAHs. Under the obtained conditions, linear chromatographic responses were achieved over the concentration ranges of 0.03-100 μg L-1 with the correlation coefficients ranging from 0.9980 to 0.9991. Limits of detection (LODs) were between 0.007 and 0.149 μg L-1 (S/N = 3). The developed SPME-HPLC/UV method was applied to selective preconcentration and sensitive determination of PAHs in water. Moreover, this fiber had good fiber preparation reproducibility and presented 120 adsorption and desorption cycles at the same time in practical SPME application.

Controllable in situ growth of novel octahedral TiO2 nanoparticles on nickel/titanium alloy fiber substrate for selective solid-phase microextraction of ultraviolet filters in water samples.

The nature and fabrication of fiber coatings with good adsorption capacity and selectivity play a decisive role in solid-phase microextraction (SPME). In this work, a novel SPME fiber was fabricated through hydrothermal in situ growth of octahedral TiO2 nanoparticles (TiO2NPs) on a superelastic nickel/titanium alloy (NiTi) wire substrate in acid solution. The resulting fiber coatings were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. Acid types, acid concentration as well as hydrothermal temperature and time were found to be effective route to manipulate the morphologies and composition of TiO2-based nanoflakes grown on the NiTi fiber substrates. At the concentration of 0.4 mol L−1 HCl as well as hydrothermal temperature of 150 °C and hydrothermal time of 12 h, TiO2NPs were in situ grown on the NiTi wire substrates. The obtained NiTi wire with the TiO2NPs coating (NiTi@TiO2NPs fiber) was employed to investigate the adsorption of some representative aromatic analytes in water samples coupling with high-performance liquid chromatography with UV detection (HPLC/UV). The results clearly demonstrate that the fiber exhibits good extraction selectivity for ultraviolet filters (UVFs). In view of good extraction selectivity for the selected UVFs, the key experimental parameters were optimized. Under the optimum conditions, the calibration curves were linear in the ranges of 0.05–100 μg L−1 with the correlation coefficients greater than 0.998. Limits of detection (LODs) were 0.007 to 0.064 μg L−1. Furthermore, the intra-day and inter-day repeatability of the proposed method with the single fiber varied from 4.3% to 6.1% and from 4.5% to 6.8%, respectively. The fiber-to-fiber reproducibility ranged from 5.8% to 8.2%. The developed SPME-HPLC/UV method was applied to selective preconcentration and sensitive determination of target UVFs from real water samples. Moreover, the fabricated fiber showed precisely controllable growth and 150 extraction and desorption cycles.

Protein Corona-Induced Extraction after Fe3+/H2o2 Degradation for Selective Preconcentration of Silver Sulphide Nanoparticles from Environmental Waters

Protein Corona-Induced Extraction after Fe3+/H2o2 Degradation for Selective Preconcentration of Silver Sulphide Nanoparticles from Environmental Waters