A practical silver nanoparticle-based adsorbent for the removal of Hg2+ from water

A novel synthesis of silver nanowires by using 6-chlorohexylzinc bromide as an additive for low haze transparent conductive films

High-quality silver nanowires (AgNWs) with a small diameter of ∼20 nm and a length of ∼40 μm were prepared by using a novel organic 6-chlorohexylzinc bromide as an assistant additive. The diameter of as-synthesized AgNWs was confirmed to be strongly dependent on the dosage of 6-chlorohexylzinc bromide. Moreover, a two-dimensional (2D) transparent conductive film (TCF) with an excellent optical performance was fabricated by as-synthesized AgNWs, which has a 90.3% transmittance and low haze value of <1.0% at a sheet resistance of 48.7 Ω sq⁻¹.

Silver nanowires with a diameter of ∼20 nm and length of 40 μm were prepared by using 6-chlorohexylzinc bromide as an additive.

Synthetic coal fly ash-derived zeolites doped with silver nanoparticles for mercury (II) removal from water

Coal fly ash-derived zeolites have attracted considerable interest in the last decade due to their use in several environmental applications such as the removal of dyes and heavy metals from aqueous solutions. In this work, coal fly ash-derived zeolites and silver nanoparticles-impregnated zeolites (nanocomposites) were synthesized and characterized by TEM/EDX, SEM/EDX, XRD, XRF, porosimetry (BET), particle size analysis (PSA) and zeta potential measurements. The synthesized materials were used for the removal of Hg²⁺ from aqueous solutions. The results demonstrated that nanocomposites can remove 99% of Hg²⁺, up to 10% and 90% higher than the removal achieved by the zeolite and the parent fly ash, respectively. Leaching studies further demonstrated the superiority of the nanocomposite over the parent materials. The Hg²⁺ removal mechanism is complex, involving adsorption, surface precipitation and amalgamation.

Photocatalytic mineralization and degradation kinetics of sulphamethoxazole and reactive red 194 over silver-zirconium co-doped titanium dioxide: Reaction mechanisms and phytotoxicity assessment

The photodegradation and phytotoxicity of the pharmaceutical antibiotic, sulphamethoxazole (SMX) and the azo-dye reactive-red-194 (RR194) under visible-light irradiation of TiO₂ nanoparticles modified by silver and zirconium was investigated. The results indicated that sulphamethoxazole and its toxic degradation by product, 3-amino-5-methylisoxazole and RR-194 could be degraded efficiently by the co-doped Zr/Ag-TiO₂ catalyst. PL studies and ROS generation results suggested that the effective charge separation was carried out while irradiation of the modified TiO₂ nanoparticles. Phytotoxicity tests demonstrated lower percentage of germination in P. vulgaris (40%), V. radiata (30%) and P. lunatus (30%) of the seeds treated with 50 ppm of SMX, compared to the seeds treated with the degradation products (100%). The results with 50 ppm of RR-194 also showed lower percentage of germination in P. vulgaris (40%), V. radiata (50%) and P. lunatus (30%) compared to the degradation products (100%). Furthermore, significant increase in root and shoot development was observed in the seeds treated with the degraded products when compared with SMX and RR-194. Overall, this study contributes to further understanding the photodegradation mechanisms, degradation products and environmental fate of SMX and RR-194 in water which helps in the evaluation and mitigation of the environmental risk of SMX and RR-194 for water reuse and crop irrigation.

Visible light photocatalytic mineralization of 17α-ethinyl estradiol (EE2) and hydrogen evolution over silver and strontium modified TiO2 nanoparticles: mechanisms and phytotoxicity assessment

This study focusses on the novel synthesis of silver and strontium modified TiO₂ nanocomposite through a sol–gel method, which was then utilized for visible light degradation of EE2 and hydrogen production for the first time.

Post-synthetically modified MOF for the A3-coupling reaction of aldehyde, amine, and alkyne

A new heterogeneous NHC catalyst (Ag-NHC-MOF) was synthesized by the post-synthetic modification of an azolium-containing metal–organic framework.

A novel multifunctional Ag and Sr2+ co-doped TiO2@rGO ternary nanocomposite with enhanced p-nitrophenol degradation, and bactericidal and hydrogen evolution activity

In the present study, a novel multifunctional Sr²⁺/Ag–TiO₂@rGO ternary hybrid photocatalyst was prepared via facile sol–gel and hydrothermal methods. The prepared catalyst was well characterized by UV-vis, XRD, Raman, HRTEM and XPS. The synthesized composite was utilised for p-NP degradation, E. coli disinfection and H₂ generation under visible light. The Sr²⁺/Ag–TiO₂@rGO catalyst showed enhanced photocatalytic H₂ evolution rate (64.3 μmol h⁻¹) compared with Ag–TiO₂@rGO (30.1 μmol h⁻¹) and TiO₂ (no activity). Nearly complete degradation of 15 mg l⁻¹p-NP was achieved over Sr²⁺/Ag–TiO₂@rGO after 3 h, while only 66% and 5% was achieved by Ag–TiO₂@rGO and TiO₂ respectively. Furthermore, TEM analysis was carried out on Escherichia coli (E. coli) before and after visible light irradiation to understand the inactivation mechanism and DNA analysis indicated no fragmentation during inactivation. Radical quantification experiments and ESR analysis suggested that ·OH and O₂˙⁻ were the main ROS in the degradation and disinfection processes. The superior photocatalytic H₂ evolution rate of Sr²⁺/Ag–TiO₂@rGO was attributed to the synergetic effect between the Ag, Sr²⁺ and TiO₂ components on the rGO surface. The localized SPR effect of Ag induced visible light generated charge carriers into the conduction band of the TiO₂ and Sr²⁺ which further transfer to the rGO for the reduction of H⁺ ions into H₂. The results suggest that Sr²⁺/Ag–TiO₂@rGO structures could not only induce separation and migration efficiency of charge carries, but also improve charge collection efficiency for enhanced catalytic activity. Thus, we believe that this work could provide new insights into multifunctional nanomaterials for applications in solar photocatalytic degradation of harmful organics and pathogenic bacteria with clean energy generation during wastewater treatment.

In the present study, a novel multifunctional Sr²⁺/Ag–TiO₂@rGO ternary hybrid photocatalyst was prepared via facile sol–gel and hydrothermal methods.

Antibacterial Electrospun Poly(vinyl alcohol)/Enzymatic Synthesized Poly(catechol) Nanofibrous Midlayer Membrane for Ultrafiltration

Two different nanofibrous antibacterial membranes containing enzymatically synthesized poly(catechol) (PC) or silver nitrate (AgNO₃, positive control) blended with poly(vinyl alcohol) (PVA) and electrospun onto a poly(vinylidene fluoride) (PVDF) basal disc to generate thin-film composite midlayers were produced for water ultrafiltration applications. The developed membranes were thoroughly characterized in terms of morphology, chemical composition, and general mechanical and thermal features, antimicrobial activity, and ultrafiltration capabilities. The electrospun blends were recognized as homogeneous. Data revealed relevant conformational changes in the PVA side groups, attributed to hydrogen bonding, high thermal stability, and residual mass. PVDF+PVA/AgNO₃ membrane displayed 100% growth inhibition of both Gram-positive and Gram-negative bacteria strains, despite the wide range of fiber diameters generated, from 24 to 125 nm, formation of numerous beads, and irregular morphology. The PVDF+PVA/PC membrane showed a good growth inhibition of Staphylococcus aureus (92%) and revealed a smooth morphology with no relevant bead formations and diameters ranging from 68 to 131 nm. The ultrafiltration abilities of the membrane containing PVA/PC were tested in a dead-end high-pressure cell (4 bar) using a reactive dye in distilled water and seawater. After 5 cycles, a maximum rejection of ≈85% with an average flux rate of 70 L m^-2 h^-1 for distilled water and ≈64% with an average flux rate of 62 L m^-2 h^-1 for seawater were determined with an overall salt rejection of ≈5%.

Gold nanozyme-based paper chip for colorimetric detection of mercury ions

In this study, we developed a facile gold nanozyme-based paper chip (AuNZ-PAD) for Hg²⁺ detection. This device has the advantages of being simple, rapid, cost effective, sensitive, selective, high throughput, and applicable to onsite detection. The colorimetric mercury assay on the AuNZ-PAD is established based on the enzyme-like catalytic activity of gold nanoparticles promoted by the formation of Au–Hg amalgam, which is correlated to the intensity of the colorimetric response resulting from the catalytic reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) and H₂O₂. Highly sensitive and selective detection of Hg²⁺ ions is achieved in both distilled and tap water samples, indicating the feasibility and applicability of our device for the determination of mercury pollution in real samples. Moreover, AuNZ-PAD analysis using a smartphone camera eliminates the need for expensive analytical equipment, thereby increasing the practicality of field monitoring of trace Hg²⁺ compared with other sensing methods.

Advanced Nanomaterials for the Removal of Chemical Substances and Microbes From Contaminated and Waste Water

The development of cost-effective, efficient and stable materials helps to provide the affordable solutions to get safe and fresh water to increasing population with health guidelines of emerging contaminants. Nanomaterials (NMs)-based techniques involve the design, synthesis, manipulation, characterization and exploitation of materials for adsorption and separation of target species from the contaminated and waste water. NMs show better adsorption capacity and catalytic for number chemical species and microbes because of their small size and large surface area that favors the purification and treatment of waste or contaminated environmental water. Here, we present the chemical properties, adsorption/removal mechanism and applications of advanced NMs such as magnetic nanoparticles (MNPs), carbon nanotubes (CNTs), graphene and graphene oxide (GO), titanium oxide (TiO2), silica (SiO2), silver (Ag), gold (Au) NPs and zeolites in effective and efficient removal of toxic metal ions, organic and inorganic chemical substances and disease-causing microbes from contaminated and wastewater.

Rational design, fabrication and characterization of a thiol-rich 3D-porous hypercrosslink polymer as a new engineered Hg2+ sorbent: enhanced selectivity and uptake

A new synergy between a porous matrix and active sites was developed to form a heterogeneous adsorbent for high efficiency and high selectivity mercury removal in drinking water.

Highly efficient simultaneous adsorption of Cd(ii), Hg(ii) and As(iii) ions from aqueous solutions by modification of graphene oxide with 3-aminopyrazole: central composite design optimization

Efficient simultaneous adsorption of heavy metal ions from solutions by modified graphene oxide with 3-aminopyrazole using central composite design modeling.

Fe2O3/Al2O3microboxes for efficient removal of heavy metal ions

Pictorial representation of removal of mercury ions using Fe₂O₃/Al₂O₃MOFs.

Application of Starch-Stabilized Silver Nanoparticles as a Colorimetric Sensor for Mercury(II) in 0.005 mol/L Nitric Acid

A sensitive and selective Hg2+optical sensor has been developed based on the redox interaction of Hg2+with starch-coated silver nanoparticles (AgNPs) in the presence of 0.005 mol L−1HNO3. The relative intensity of the localized surface plasmon absorption band of AgNPs at 406 nm is linearly dependent on the concentration of Hg2+with positive slope for the concentration range 0–12.5 μg L−1and negative slope for the concentration range 25–500 μg L−1. Experiments performed demonstrated that metal ions (Na+, K+, Mg2+, Ca2+, Pb2+, Cu2+, Zn2+, Cd2+, Fe3+, Co2+, and Ni2+) do not interfere under the same conditions, due to the absence of oxidative activity of these ions, which guarantees the high selectivity of the proposed optical sensor towards Hg2+. The limits of detection and quantification were found to be 0.9 µg L−1and 2.7 µg L−1, respectively, and relative standard deviations varied in the range 9–12% for Hg content from 0.9 to 12.5 μg L−1and 5–9% for Hg levels from 25 to 500 μg L−1. The method was validated by analysis of CRM Estuarine Water BCR505. A possible mechanism of interaction between AgNPs and Hg2+for both concentration ranges was proposed on the basis of UV-Vis, TEM, and SAED analyses.

One-step fabrication and characterization of a poly(vinyl alcohol)/silver hybrid nanofiber mat by electrospinning for multifunctional applications

Preparation and application of a poly(vinyl alcohol)/silver hybrid nanofiber mat by electrospinning.

The removal of mercury (II) from water by Ag supported on nanomesoporous silica

In this study, the synthesis of SBA-15/Ag nanocomposite materials with different amounts of silver (2.5, 5, and 10 %) has been investigated under acidic conditions by using P123 as a template via the direct method. The nanocomposites of SBA-15 were synthesized by the same method and by the addition of silver salt. Finally, the nanocomposite materials were examined for the removal of mercury ions from wastewater as an adsorbent by the reverse titration method. Characterization was carried out through x-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption-desorption (Brunauer-Emmett-Teller). XRD spectra confirmed the presence of silver nanoparticles within the amorphous silica matrix of SBA-15. The Barrett-Joyner-Halenda analysis showed that SBA-15 and SBA-15/Ag have a narrow pore size distribution. SEM images demonstrated that the morphology of the matrix of SBA-15 is in spherical state. Furthermore, wavelength dispersive x-ray spectroscopy identified the presence and distribution of silver nanoparticles inside the pore channels and outside of them. Typical TEM images of SBA-15 and SBA-15/Ag (5 wt.%) indicated a regular hexagonal pore structure with long-range order and long channels. In SBA-15/Ag (5 wt.%) sample, the nanoparticles of silver was found into the pores and outside of them. The removal of mercury ions from wastewater using mesoporous silica nanocomposite containing silver nanoparticles was studied by the reverse titration analysis. The best capacity of adsorption of mercury ions from wastewater was obtained for SBA-15/Ag (5 wt.%) sample, which was equal to 42.26 mg/g in 20 min at pH of 7. The Freundlich model was used to explain the adsorption characteristics for the heterogeneous surface, and [Formula: see text] (adsorption capacity) and n (adsorption intensity) were determined for Hg (II) ion adsorption on SBA-15/Ag nanocomposite materials with different amounts of silver (2.5, 5, and 10 %). The value of R2 was about 0.99, 0.99, 0.98, and 0.98 and Kf was about 42, 48, 58, and 58 mg/g for SBA-15/Ag, SBA-15/Ag (2.5 %), SBA-15/Ag (5 %), and SBA-15/Ag (10 %), respectively. Furthermore, the values of n >1 show a favorable adsorption process for Hg (II) ion adsorption on SBA-15/Ag nanocomposite materials. Moreover, the Langmuir isotherm model evaluation showed that the correlation coefficients for all concentrations were R2 >0.99, indicating that Hg (II) ions were adsorbed on the surface of SBA-15/Ag via chemical and physical interaction. Additionally, the analytic hierarchy process (AHP) and Technique of Order Preference Similarity to the Ideal Solution (TOPSIS) methods that depend on the criteria of the surface area, amount of adsorbent, pore volume, and cost of synthesis were used. The evaluation of results showed that the best sample was SBA-15/Ag (5 wt.%). Furthermore, the research work highlighted the antibacterial nanocomposite with suitable adsorption of Hg (II) ions from water solutions and supported its potential for environmental applications. This nanocomposite can be used in the absorption domain of Hg (II) ions from water solutions.

Complete reaction mechanisms of mercury oxidation on halogenated activated carbon

The reaction mechanisms of mercury (Hg) adsorption and oxidation on halogenated activated carbon (AC) have been completely studied for the first time using density functional theory (DFT) method. Two different halogenated AC models, namely X-AC and X-AC-X (X=Cl, Br, I), were adopted. The results revealed that HgX is found to be stable-state on the AC edge since its further desorption from the AC as HgX, or further oxidation to HgX2, are energetically unfavorable. Remarkably, the halide type does not significantly affect the Hg adsorption energy but it strongly affects the activation energy barrier of HgX formation, which obviously increases in the order HgI<HgBr<HgCl. This trend coincides with the experimental observations which reported the efficiency of halogen impregnated AC for Hg elimination significantly decreases as I-AC>Br-AC>Cl-AC. Thus, the study of the complete reaction mechanism is essential because the adsorption energy can not be used as a guideline for the rational material design in the halide impregnated AC systems. The activation energy is an important descriptor for the predictions of sorbent reactivity to the Hg oxidation process.

A visible light mediated synergistic catalyst for effective inactivation of E. coli and degradation of azo dye Direct Red-22 with mechanism investigation

Novel zirconium and silver co-doped TiO₂ nanoparticles were fabricated and utilized as effective multifunctional visible light photocatalysts for inactivation of bacteria (E. coli) as well as degradation of azo dye (Direct Red-22) for the first time.

Dragon's blood-aided synthesis of Ag/Ag2O core/shell nanostructures and Ag/Ag2O decked multi-layered graphene for efficient As(iii) uptake from water and antibacterial activity

Excellent As(iii) uptake and antibacterial activities of Ag/Ag₂O core/shell and multi-layered graphene nanostructures obtained with the aid of Dragon's blood.

Mechanistic study of visible light driven photocatalytic degradation of EDC 17α-ethinyl estradiol and azo dye Acid Black-52: phytotoxicity assessment of intermediates

The present study evaluated the phytotoxicity of degraded intermediates of an endocrine-disrupting compound (EDC) 17α-ethinyl estradiol (EE2) and toxic azo dye Acid Black-52 (AB-52) in photocatalytic degradation.

Antimicrobial electrospun silver-, copper- and zinc-doped polyvinylpyrrolidone nanofibers

The use of electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc nanoparticles was studied to prepare antimicrobial mats using silver and copper nitrates and zinc acetate as precursors. Silver became reduced during electrospinning and formed nanoparticles of several tens of nanometers. Silver nanoparticles and the insoluble forms of copper and zinc were dispersed using low molecular weight PVP as capping agent. High molecular weight PVP formed uniform fibers with a narrow distribution of diameters around 500 nm. The fibers were converted into an insoluble network using ultraviolet irradiation crosslinking. The efficiency of metal-loaded mats against the bacteria Escherichia coli and Staphylococcus aureus was tested for different metal loadings by measuring the inhibition of colony forming units and the staining with fluorescent probes for metabolic viability and compromised membranes. The assays included the culture in contact with mats and the direct staining of surface attached microorganisms. The results indicated a strong inhibition for silver-loaded fibers and the absence of significant amounts of viable but non-culturable microorganisms. Copper and zinc-loaded mats also decreased the metabolic activity and cell viability, although in a lesser extent. Metal-loaded fibers allowed the slow release of the soluble forms of the three metals.

Encapsulated Silver Nanoparticles Can Be Directly Converted to Silver Nanoshell in the Gas Phase

We report, for the first time, that an encapsulated silver nanoparticle can be directly converted to a silver nanoshell through a nanoscale localized oxidation and reduction process in the gas phase. Silver can be etched when exposed to a mixture of NH3/O2 gases through a mechanism analogous to the formation of aqueous Tollens' reagent, in which a soluble silver-ammonia complex was formed. Starting with Ag@resorcinol-formaldehyde (RF) resin core-shell nanoparticles, we demonstrate that RF-core@Ag-shell nanoparticles can be prepared successfully when the etching rate and RF thickness were well controlled. Due to the strong surface plasmon resonance (SPR) coupling effect among neighboring silver nanoparticles, the RF@Ag nanoparticle showed great SPR and SERS performance. This process provides a general route to the conversion of Ag-core to Ag-shell nanostructures and might be extended to other systems.

Antimicrobial Activity Evaluation on Silver Doped Hydroxyapatite/Polydimethylsiloxane Composite Layer

The goal of this study was the preparation, physicochemical characterization, and microbiological evaluation of novel hydroxyapatite doped with silver/polydimethylsiloxane (Ag:HAp-PDMS) composite layers. In the first stage, the deposition of polydimethylsiloxane (PDMS) polymer layer on commercially pure Si disks has been produced in atmospheric pressure corona discharges. Finally, the new silver doped hydroxyapatite/polydimethylsiloxane composite layer has been obtained by the thermal evaporation technique. The Ag:HAp-PDMS composite layers were characterized by various techniques, such as Scanning Electron Microscopy (SEM), Glow Discharge Optical Emission Spectroscopy (GDOES), and X-ray photoelectron spectroscopy (XPS). The antimicrobial activity of the Ag:HAp-PDMS composite layer was assessed against Candida albicans ATCC 10231 (ATCC-American Type Culture Collection) by culture based and confirmed by SEM and Confocal Laser Scanning Microscopy (CLSM) methods. This is the first study reporting the antimicrobial effect of the Ag:HAp-PDMS composite layer, which proved to be active against Candida albicans biofilm embedded cells.

Size and Aging Effects on Antimicrobial Efficiency of Silver Nanoparticles Coated on Polyamide Fabrics Activated by Atmospheric DBD Plasma

This work studies the surface characteristics, antimicrobial activity, and aging effect of plasma-pretreated polyamide 6,6 (PA66) fabrics coated with silver nanoparticles (AgNPs), aiming to identify the optimum size of nanosilver exhibiting antibacterial properties suitable for the manufacture of hospital textiles. The release of bactericidal Ag(+) ions from a 10, 20, 40, 60, and 100 nm AgNPs-coated PA66 surface was a function of the particles' size, number, and aging. Plasma pretreatment promoted both ionic and covalent interactions between AgNPs and the formed oxygen species on the fibers, favoring the deposition of smaller-diameter AgNPs that consequently showed better immediate and durable antimicrobial effects against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. Surprisingly, after 30 days of aging, a comparable bacterial growth inhibition was achieved for all of the fibers treated with AgNPs <100 nm in size. The Ag(+) in the coatings also favored the electrostatic stabilization of the plasma-induced functional groups on the PA66 surface, thereby retarding the aging process. At the same time, the size-related ratio (Ag(+)/Ag(0)) of the AgNPs between 40 and 60 nm allowed for the controlled release of Ag(+) rather than bulk silver. Overall, the results suggest that instead of reducing the size of the AgNPs, which is associated with higher toxicity, similar long-term effects can be achieved with larger NPs (40-60 nm), even in lower concentrations. Because the antimicrobial efficiency of AgNPs larger than 30 nm is mainly ruled by the release of Ag(+) over time and not by the size and number of the AgNPs, this parameter is crucial for the development of efficient antimicrobial coatings on plasma-treated surfaces and contributes to the safety and durability of clothing used in clinical settings.

Removal of trace mercury (II) from aqueous solution by in situ MnO(x) combined with poly-aluminum chloride

Removal of trace mercury from aqueous solution by Mn (hydr)oxides formed in situ during coagulation with poly-aluminum chloride (PAC) (in situ MnO(x) combined with PAC) was investigated. The efficiency of trace mercury removal was evaluated under the experimental conditions of reaction time, Mn dosage, pH, and temperature. In addition, the ionic strength and the initial mercury concentration were examined to evaluate trace mercury removal for different water qualities. The results clearly demonstrated that in situ MnO(x) combined with PAC was effective for trace mercury removal from aqueous solution. A mercury removal ratio of 9.7 μg Hg/mg Mn was obtained at pH 3. Furthermore, at an initial mercury concentration of 30 μg/L and pH levels of both 3 and 5, a Mn dosage of 4 mg/L was able to lower the mercury concentration to meet the standards for drinking water quality at less than 1 μg/L. Analysis by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy suggests that the hydroxyls on the surface of Mn (hydr)oxides are the active sites for adsorption of trace mercury from aqueous solution.

Nanosphere monolayer on a transducer for enhanced detection of gaseous heavy metal

This study reports for the first time that polystyrene monodispersed nanosphere monolayer (PS-MNM) based Au (Au-MNM) and Ag (Ag-MNM) nanostructures deposited on quartz crystal microbalance (QCM) transducers can be used for nonoptical based chemical sensing with extremely high sensitivity and selectivity. This was demonstrated by exposing the Au-MNM and Ag-MNM based QCMs to low concentrations of Hg(0) vapor in the presence interferent gas species (i.e., H2O, NH3, volatile organics, etc.) at operating temperatures of 30 and 75 °C. At 30 °C, the Au-MNM and Ag-MNM based QCMs showed ∼16 and ∼20 times higher response magnitude toward Hg(0) vapor concentration of 3.26 mg/m(3) (364 parts per billion by volume (ppbv)) relative to their unmodified control counterparts, respectively. The results indicated that the extremely high sensitivity was not due to the increased surface area (only 4.62 times increase) but due to their long-range interspatial order and high number of surface defect formation which are selectively active toward Hg(0) vapor sorption. The Au-MNM and Ag-MNM also had more than an order of magnitude lower detection limits (<3 ppbv) toward Hg(0) vapor compared to their unmodified control counterparts (>30 ppbv). When the operating temperature was increased from 30 to 75 °C, it was found that the sensors exhibited lower drift, better accuracy, and better selectivity toward Hg(0) vapor but at the compromise of higher detection limits. The high repeatability (84%), accuracy (97%), and stability of Au-MNM in particular make it practical to potentially be used as nonspectroscopic based Hg(0) vapor sensor in many industries either as mercury emission monitoring or as part of a mercury control feedback system.