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Innovations in wearable sweat sensors hold great promise to provide deeper insights into molecular level health information non‐invasively. Lactate, a key metabolite present in sweat, holds immense significance in assessing physiological conditions and performance in sports physiology and health sensing. This paper presents the development and characterization of stretchable electrodes with ultrahigh active surface area of 648 % for lactate sensing. The as‐printed stretchable electrodes were functionalized with an electron transfer layer comprising Toluidine Blue O and multi‐walled carbon nanotubes (MWCNTs), and an enzymatic layer consisting of lactate dehydrogenase with β‐Nicotinamide adenine dinucleotide as the cofactor for lactate selectivity. This sensor achieves a dual‐signal read‐out in which both electrochemical and fluorescence signals were obtained during lactate detection, demonstrating promising sensor performance in terms of sensitivity and reliability. We demonstrate the robustness of the dual‐signal sensor under simulated conditions of physical deformation and shifted excitation. Under these compromised conditions, the performance of the stretchable electrodes remained largely unaffected, showcasing their potential for robust and adaptable sensing platforms in wearable health monitoring applications. [ABSTRACT FROM AUTHOR]

Herein, we investigate the potential application of a composite consisting of PEDOT:PSS/Graphene, deposited via spray coating on a flexible substrate, as an autonomous conducting film for applications in wearable biosensor devices. The stability of PEDOT:PSS/Graphene is assessed through electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and linear polarization (LP) during exposure to an artificial sweat electrolyte, while scanning electron microscopy (SEM) was employed to investigate the morphological changes in the layer following these. The results indicate that the layers exhibit predominant capacitive behavior in the potential range of −0.3 to 0.7 V vs. Ag/AgCl, with a cut-off frequency of approximately 1 kHz and retain 90% capacity after 500 cycles. Aging under exposure to air for 6 months leads only to a minor increase in impedance, demonstrating potential for storage under non-demanding conditions. However, prolonged exposure (>48 h) to the artificial sweat causes significant degradation, resulting in an impedance increase of over 1 order of magnitude. The observed degradation raises important considerations for the long-term viability of these layers in wearable biosensor applications, prompting the need for additional protective measures during prolonged use. These findings contribute to ongoing efforts to enhance the stability and reliability of conducting materials for biosensors in health care and biotechnology applications. [ABSTRACT FROM AUTHOR]

Wearable device shell materials will inevitably be corroded by human sweat during use. The purpose of this study is to construct three composite films of CrSiCN, CrBCN and CrSiBCN with corrosion resistance on silicon wafers and 316L stainless steel substrates by using closed-field unbalanced magnetron sputtering technology as protective films, to protect the corrosion of shell materials. The electrochemical behavior of Si and B element doped films under acidic and alkaline artificial sweat was studied by electrochemical noise, AC impedance and potentiodynamic polarization electrochemical measurement techniques, and the microstructural changes of the films were characterized by scanning electron microscopy, x-ray diffraction and laser Raman spectroscopy. Electrochemical test results show that the films exhibit a higher corrosion rate compared to alkaline artificial sweat due to the higher concentration of chloride ions, hydrogen ions, and lactic acid corrosive ions in acidic artificial sweat. The results also demonstrated that the inhibitory effect of a high concentration of hydrogen ions in acidic artificial sweat resulted in a relatively low surface oxygen content, whereas the doping of the boron element promoted the growth of passive film on the coating surface, thereby decreasing the corrosion rate of CrBCN film in acidic sweat. Furthermore, the high concentration of hydroxyl ions in alkaline artificial sweat accelerates the electrochemical reactions of passive film growth (mainly chromium oxides and hydroxides), hence enhancing the corrosion resistance of the CrSiCN film with its denser and smoother surface. [ABSTRACT FROM AUTHOR]

A solid-phase microextraction (SPME) injection gas chromatography was validated with the flame ionization detection method (GC-FID) using a capillary column to detect ethanol. The method was used to determine ethanol in fluids with biomedical, clinical, and forensic importance, including water, phosphate-buffered saline (PBS), and artificial sweat. The strategy produced good peak resolution and showed a linear correlation between the concentration and peak areas for ethanol in all matrices. The inter- and intra-day precisions of the method were below 15.5% and 6.5%, respectively, varying according to the matrix. The method achieved detection limits below 1.3 mg/L, varying according to the matrix. Lower limits were obtained for the aqueous solution (0.22 mg/L), followed by the PBS solution (0.96 mg/L), and finally, the sweat solution (1.29 mg/L). This method is easy to perform and suitable for use in routine clinical biochemistry and forensic laboratories, allowing ethanol detection at lower concentrations using lower temperature and time of extraction, when compared with other studies. [ABSTRACT FROM AUTHOR]

Silver coating in its jewelry application needs to resist tarnishing as well as wear. The corrosion and tribological behavior of pulse reverse current (PRC) and the addition of SiC 45-60 nm-size nanoparticles in the Ag-Ge coating on copper substrate were investigated. The contact angle, open circuit potential and electrochemical polarization in ammonium sulfide and artificial sweat media and thioacetamide corrosion were studied. Moreover, the pin-on-disc method and microhardness were used to assess the wear behavior of the coatings. FE-scanning electron microscopy equipped with energy dispersive spectroscopy and x-ray diffraction patterns were used. During reverse time in PRC process, the already reduced hydrogen on cathode surface was released and resulted in fine-grained microstructure, reduction of internal defects and smooth surface, which in turn improved the corrosion resistance of the coating. PRC together with nano-SiC changed the coating behavior from super-hydrophilic to hydrophobicity. Corrosion analysis showed that PRC sample possessed the best resistance to corrosion in both ammonium sulfide as well as artificial sweat. Although SiC addition reduced the corrosion resistance, still was much higher than that of direct current sample. Analyses of the wear behavior of the deposited film showed that samples containing SiC nanoparticles obtained superior wear resistance than samples without SiC. The dominant wear mechanism in both DC and PRC coatings was the delamination mechanism, whereas the wear mechanism in the coatings contained 4 and 8 g SiC in electrolyte was the adhesive wear mechanism. [ABSTRACT FROM AUTHOR]

Corrosion resistance of thermo active alloy and Gold 18K alloy immersed in artificial sweat in the absence and presence of 100 ppm of NaCl has been investigated by polarization study and AC impedance spectra. It is observed that corrosion resistance of thermo active alloy and also Gold 18K alloy immersed in artificial sweat in the presence of 100 ppm of NaCl increases. Hence it is concluded that people wearing ornaments made of these two alloys need not worry about the excess of sodium chloride in their sweat. When thermo active alloy is immersed in artificial sweat in the presence of 100 ppm of NaCl, linear polarization resistance value increases from 1760283 Ohm cm2 to 9506106 Ohm cm2 ; corrosion current decreases from 1.845x10-8 to 4.008x10-9 A/cm2 ; charge transfer resistance value increases from 4884 Ohmcm2 to 12210 Ohm cm2 ; impedance value increases from 4.367 to 4.8; double layer capacitance decreases from 1.0442 x10 -9 to 4.1769x10-10 F/cm2 , and phase angle increases from 48.1 to 66.34°. When Gold 18K alloy is immersed in artificial sweat in the presence of 100 ppm of NaCl, linear polarization resistance value increases from 1079199 Ohmcm2 to 2385141 Ohm cm2 ; corrosion current decreases from 4.036x10-8 to 0.1966 x 10 -8A/cm2 ; charge transfer resistance increases from 4291 Ohm cm2 to 48880 Ohm cm2 ; impedance value increases from 4.652 to 5.114; double layer capacitance decreases from 1.189 x10-9 to 1.0434 x10-10 F/cm2 , and phase angle increases from 61 to 88.

Corrosion resistance of SS 18/8 alloy and Gold 22 K alloy immersed in artificial sweat in the absence and presence of 100 ppm of D-Glucose has been investigated by polarization study and AC impedance spectra. It is observed that corrosion resistance of SS 18/8 alloy and also Gold 22 K alloy immersed in artificial sweat in the presence of 100 ppm of D-Glucose decreases. Hence it is concluded that people wearing ornaments made of these two alloys need to worry about the excess of D-Glucose in their sweat. When SS 18/8 alloy is immersed in artificial sweat in the presence of 100 ppm of D-Glucose, Linear Polarisation Resistance value decreases from 589308032 Ohmcm2 to 87905 Ohmcm2 ; corrosion current increases from 8.923x10-11A/cm2 to 4.008x10-9 A/cm2 ; charge transfer resistance value increases from 4884 Ohmcm2 to 3.168 x10-7 12210 Ohmcm2 ; impedance value decreases from 8.023 to 4.008; double layer capacitance increases from 8.9099x10-14F/cm2 to 1.4868 x10-9 F/cm2 , and phase angle decreases from 94° to 54°. When Gold 22 K alloy is immersed in artificial sweat in the presence of 100 ppm of DGlucose, Linear Polarisation Resistance value decreases from 4248438 Ohmcm2 to 236576 Ohmcm2 ; corrosion current increases from 8.038 x10-9A/cm2 to 1.546 x10-7A/cm2 ; charge transfer resistance decreases from 23680 Ohmcm2 to 6336 Ohmcm2 ; impedance value decreases from 4.647to 4.567; double layer capacitance increases from 2.154 x10-10 F/cm2 to 8.049x10-10 F/cm2 , and phase angle increases from 66° to 64°.

Wearable pH sensors for sweat analysis have garnered significant scientific attention for the detection of early signs of many physiological diseases. In this study, a MoS2‐polyaniline (PANI) modified screen‐printed carbon electrode (SPCE) is fabricated and used as a sweat biosensor. The exfoliated MoS2 nanosheets are drop casted over an SPCE and are functionalized by a conducting polymer, polyaniline (PANI) via the electropolymerization technique. The as‐fabricated biosensor exhibits high super‐Nernstian sensitivity of −70.4 ± 1.7 mV pH−1 in the linear range of pH 4 to 8 of 0.1 m standard phosphate buffer solution (PBS), with outstanding reproducibility. The sensor exhibits excellent selectivity against the common sweat ions including Na+, Cl−, K+, and NH4+ with tremendous long‐term stability over 180 min from pH 4 to 6. The enhanced active surface area and better electrical conductivity as a consequence of the synergistic effect between MoS2 and PANI are correlated with the boosted performance of the as‐produced biosensor. The feasibility of the sensor is further examined using an artificial sweat specimen and the successful detection confirms the potential of the biosensor for a real‐time noninvasive, skin attachable, and flexible wearable pH sensor. [ABSTRACT FROM AUTHOR]

This study aims to develop a comprehensive process to evaluate the leaching behavior of 3D-printed nanocomposite samples as candidate materials for potential use in wearable devices. The study involves the immersion of the 3D-printed test coupons, produced via Fused Filament Fabrication (FFF), into artificial sweat and deionized water in a controlled environment provided by a dissolution apparatus. Three distinct nanocomposite filaments were used, each consisting of different polymer matrices: thermoplastic polyurethane (TPU), copolyester (TX1501), and polyamide (PA12). The additives incorporated within these filaments encompassed silver nanoparticles (AgNPs), chopped carbon fibers (CCFs), and super paramagnetic iron oxide nanoparticles (SPIONs), respectively. The current study aims to identify potential risks associated with the release of nanomaterials and additives, through SEM/EDX analysis and in vitro measurements of proinflammatory cytokines. Furthermore, this research contributes to the advancement of safe and reliable 3D-printed materials for wearable technologies, fostering their widespread adoption in various applications. [ABSTRACT FROM AUTHOR]

Corrosion resistance of Gold 21K alloy immersed in artificial sweat in the absence and presence of 100 ppm of urea and also 100 ppm of D-Glucose has been investigated by polarization study and AC impedance spectra. It is observed that Corrosion resistance of Gold 21K alloy immersed in artificial sweat in the presence of 100 ppm of urea / D-Glucose increases. Hence it is concluded that people wearing ornaments made of Gold 21K alloy need not worry about the excess of urea / D-Glucose in their sweat. When Gold 21K alloy is immersed in artificial sweat in the presence of 100 ppm of urea, Linear Polarisation Resistance value increases from 103389Ohmcm2 to 123437Ohmcm2 ; corrosion current decreases from 4.036 x10-7A/cm2 to 3.308 x10-7A/cm2 ; charge transfer resistance value increases from 10490 Ohmcm2 to 14070 Ohmcm2 ; impedance value increases from 4.253 to 4.324; double layer capacitance decreases from 4.862x10-10 F/cm2 to 3.625x10-10 F/cm2 , and phase angle increases from 38.91 to 70.14. When Gold 21K alloy is immersed in artificial sweat in the presence of 100 ppm of D-Glucose, Linear Polarisation Resistance value increases from 103389Ohmcm2 to 4817257Ohmcm2 ; corrosion current decreases from 4.036 x10-7A/cm2 to 0.161x10-7A/cm2 ; charge transfer resistance increases from 10490Ohmcm2 to 33300Ohmcm2 ; impedance value increases from 4.253 to 4.977; double layer capacitance decreases from 4.862x10-10 F/cm2 to 1.5315x10-10 F/cm2 , and phase angle increases from 38.91° to 79.74°.

It is well known that potentiometric sensors provide a versatile, cost‐effective, and efficient platform for wearable applications. Unfortunately, mass production and commercialization of such devices is often constrained by the requirement of a calibration step, which is due to the poor sensor‐to‐sensor reproducibility and the need of conditioning the electrodes in the analyte before use. Herein, we fabricated calibration‐free flexible sensors including ion‐selective electrode and reference electrode by integrating single‐walled carbon nanotubes (SWCNTs) with poly(3‐octylthiophene) (POT) and applying on polyethylene terephthalate (PET) substrate. The developed sodium and potassium ion‐selective electrodes (ISEs) display excellent repeatability, selectivity, stability as well as high sensor‐to‐sensor reproducibility, with a standard deviation of as low as 1.0 mV in artificial sweat microliter samples volume. [ABSTRACT FROM AUTHOR]

Electrodes based on PEDOT:PSS are gaining increasing importance as conductive electrodes and functional layers in various sensors and biosensors due to their easy processing and biocompatibility. This study investigates PEDOT:PSS/graphene layers deposited via spray coating on flexible PET substrates. The layers are characterized in terms of their morphology, roughness (via AFM and SEM), and electrochemical properties in artificial sweat using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The layers exhibit dominant capacitive behavior at low frequencies, with cut-off frequencies determined for thicker layers at 1 kHz. The equivalent circuit used to fit the EIS data reveals a resistance of about three orders of magnitude higher inside the layer compared to the charge transfer resistance at the solid/liquid interface. The capacitance values determined from the CV curves range from 54.3 to 122.0 mF m−2. After 500 CV cycles in a potential window of 1 V (from −0.3 to 0.7 V), capacitance retention for most layers is around 94%, with minimal surface changes being observed in the layers. The results suggest practical applications for PEDOT:PSS/graphene layers, both for high-frequency impedance measurements related to the functioning of individual organs and systems, such as impedance electrocardiography, impedance plethysmography, and respiratory monitoring, and as capacitive electrodes in the low-frequency range, realized as layered PEDOT:PSS/graphene conductive structures for biosignal recording.

Seventeen elements were determined in various drumheads in order to establish the elemental composition of the samples. Eleven samples were analyzed by inductively coupled plasma – mass spectrometry (ICP-MS) and the concentrations of seventeen metals (Be, Na, Mg, Ni, Al, Pb, Fe, As, Cr, Co, Cu, Se, Cd, Ru, Pd, Sn, and Sb) were determined. Migration experiments using artificial sweat were performed for three elements (As, Cr, Pb) to evaluate their extractable fractions. Exposure via dermal route to heavy metals generally receives less attention than exposure via inhalation or oral pathways. Metal determination may be beneficial to the polymer industry since heavy metals in polymers may contribute to problems during the manufacturing process. Characterization studies were performed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Be, Se, Ru, and Pd were not detected in any samples. The concentrations of the metals were from 72.84 to 354.9 µg/g for Sb, 357.9 to 15,750 ng/g for Pb, 0.28 to 121.1 µg/g for As, 101.9 to 501.6 ng/g for Cu, 383.1 to 1536 ng/g for Ni, 11.46 to 124.0 µg/g for Fe, 319.7 to 1046 ng/g for Cr, 213.2 to 1035 µg/g for Al, 1.74 to 1213 µg/g for Mg, and 118.5 to 892.5 µg/g for Na. [ABSTRACT FROM AUTHOR]

Keywords: allergic contact dermatitis; artificial sweat; cosmetic pigments; metals EN allergic contact dermatitis artificial sweat cosmetic pigments metals 550 553 4 11/11/22 20221201 NES 221201 Both nickel (Ni) and cobalt (Co) are common skin sensitizers known to cause contact allergy,1 not only existing in alloys but also in different consumer products, such as cosmetics,2 even though not intentionally added. The ASW-soluble fractions of Ni were lower than the total contents and were only observed for three pigments (yellow (ID 1), pink (ID 3) and purple (ID 4)), in amounts ranging from 2.4 to 5.5 g Ni/g pigment. All coloured pigments (IDs 1-5), and one of the white pigments (ID 6), contained detectable amounts of Ni, whereas only the yellow, purple and black pigments (IDs 1, 4, 5) also contained Co. [Extracted from the article]

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In this study the silver species were identified that leached into artificial sweat from commercially available clothing products that were in direct contact with skin. Single particle-inductively coupled plasma mass-spectrometry (SP-ICP-MS) is capable of simultaneously determining silver nanoparticles (AgNPs) and dissolved silver (Ag+), especially when dwell time is used in microsecond range. The effect of Ag+ concentration for the determination of 40 and 70 nm AgNPs was investigated and AgNPs were characterized accurately up to 2 ng mL−1 and 15 ng mL−1 Ag+, respectively. Under the optimized conditions, the limit of detection for nanoparticle number concentration (LODconc) and the limit of detection for nanoparticle size (LODsize) of the proposed SP-ICP-MS method were 5.5 × 102 particle mL−1 and 17 nm, respectively. According to the results, silver was present in artificial sweat solution in the dissolved form, which was confirmed by a spectrofluorometric assay and ultracentrifugation. In addition, the released quantity of silver from underwear was higher than from socks, which may be related to the differences in the textiles and their manufacturing processes. [ABSTRACT FROM AUTHOR]

Thermochromic inks, materials that change color at a certain temperature, are increasingly used on papers and other materials in the areas of design, commercials, and security printing. Pseudo-estrogen bisphenol A (BPA) may be one of their main compounds present in mass fractions of up to several percent. In this work, the mass fractions of BPA in thermochromic prints on seven types of paper were determined. Migration of BPA from the surface of the thermochromic print to artificial sweat solutions was investigated as well. Total amount of BPA in papers with thermochromic prints was determined by an HPLC-UV method with ultrasonic-assisted extraction in methanol developed and validated in this work. Total amount of BPA, which ranged from 0.126 to 0.778 mg/g, was compared with the amounts extracted under the same conditions in two artificial human sweat solutions, which differed in chemical composition, ionic strength, and pH-value. Mass fractions of BPA extracted with artificial sweat solutions were from 0.047 to 0.175 mg/g with respect to the mass of the paper. On average, the mass fraction of BPA was four times less when extracted with artificial sweat solutions than the maximal amount extracted with methanol. The amounts of extracted BPA raise a concern of health risk through dermal exposure to BPA from thermochromic prints on paper. [ABSTRACT FROM AUTHOR]

Element sensitization is frequent cause of allergic contact dermatitis, and Ni is the main reason for this condition owing to daily use of different Ni-containing items. European Union established a limit of 0.2 μg/cm2/week Ni release for the items by the Ni Directive in 2004. The aim of this study was to determine the amount of element release of imitation earrings sold in different points of Istanbul with different prices and consider the element release levels including 29 trace and toxic elements. After calculation of released nickel amounts, 31.80% of earrings (71 of 223) were observed over the limit of European Commission Directive's migration limit. Minimum and maximum nickel release amounts were found as 0.21 and 30.11 μg/cm2/week, respectively, and mean level was found 3.24 μg/cm2/week among 71 positive earrings. Results showed that essential part of imitation earrings used especially by women release nickel particles over the European Commission Directive's migration limit. In addition, other elements such as Cu, Cr, and Co were found to be in the structure of the imitation earrings, as well as high amounts of toxic element Pb. [ABSTRACT FROM AUTHOR]

Abstract Nanostructured metal oxides offer unique advantages for their sensing capabilities hence have been studied immensely. In the context of Mn 3 O 4 films, this study focuses on the sweat sensing prospects of these advanced materials using SILAR method, for the first time. Mn 3 O 4 films were successfully produced with varying thicknesses using SILAR method effectively. This repeatable process allowed these films to be tested in varying artificial sweat concentrations and it was found that Mn 3 O 4 films are very responsive to varying sweat concentrations. Morphological, structural, and optical measurements showed the successful growth of Mn 3 O 4 films with good uniformity, crystallinity, and smooth surface characteristics. Amperometric measurements with and without sweat concentrations showed that Mn 3 O 4 films can indeed be used for sweat sensing applications. [ABSTRACT FROM AUTHOR]

Nickel (Ni) and cobalt (Co) are the most common metal allergens upon skin contact at occupational settings and during consumer handling of metals and alloys. A standardized test (EN, 1811) exists to assess Ni release from articles of metals and alloys in massive forms intended for direct and prolonged skin contact, but no corresponding test exists for other materials such as powders or massive forms of alloys placed on the market or to determine the release of Co, for which only limited data is available. Differences in Ni and Co release from massive forms of a range of common stainless steels and some high-alloyed grades compared to Ni and Co metals were therefore assessed in artificial sweat for 1 week at 30 °C according to EN 1811. A comparable modified test procedure was elaborated and used for powders and some selected massive alloys. All alloys investigated released significantly less amount of Ni (100–5000-fold) and Co (200–400,000-fold) compared with Ni and Co metal, respectively. Almost all alloys showed a lower bioaccessible concentration (0.007–6.8 wt% Ni and 0.00003–0.6 wt% Co) when compared to corresponding bulk alloy contents (0.1–53 wt% Ni, 0.02–65 wt% Co). Observed differences are, among other factors, related to differences in bulk composition and to surface oxide characteristics. For the powders, less Ni and Co were released per surface area, but more per mass, compared to the corresponding massive forms. Image 1 • Bioaccessibility test of Co and Ni released from metals/alloys in artificial sweat. • Modification of the EN 1811 standard to assess bioaccessible Ni and Co from powders. • Ni release from alloys (0.1–53 wt% Ni) 100–5000 times lower than from Ni metal. • Co release from alloys (0.02–65 wt% Co) 200–400,000 times lower than from Co metal. • Less metal release per surface area, but higher per mass, for powders vs. massives. [ABSTRACT FROM AUTHOR]

In this paper, we aim to study the effects of artificial sweat components on the photo-fading of reactive dyes on cotton fabrics. Two standards of artificial perspiration were tested according to the Japanese Industrial Standard (JIS L 0888 standard) and the Association for Textile Technical Study (ATTS standard), respectively. The light and perspiration stability of reactive dyes was characterized using the color difference value (DE). Standard orthogonal experiments were designed to study the influences of each artificial sweat component and the interaction between these components on the photo-fading reaction of the selected reactive dyes. The results indicated that L-histidine monohydrochloride monohydrate (0.5 g/L) was the dominant influencing factor on the light and perspiration stability of the reactive dyes exposing under both standards of artificial perspiration. In the JIS L 0888 standard, sodium chloride (5.0 g/L) played the significant role in the photo-fading reaction of the reactive dyes, while the influences caused by other components could be neglected. In the ATTS standard, sodium chloride (5.0 g/L), DL-aspartic acid (0.5 g/L) and glucose (5.0 g/L) aggravated the photo-fading of the selected reactive dyes. [ABSTRACT FROM AUTHOR]

Analysis of sweat is of interest for a variety of diagnosis and monitoring applications in healthcare. In this work, detailed measurements of the dielectric properties of solutions representing the major components of sweat are presented. The measurements include aqueous solutions of sodium chloride (NaCl), potassium chloride (KCl), urea, and lactic acid, as well as their mixtures. Moreover, mixtures of NaCl, KCl, urea, and lactic acid, mimicking artificial sweat at different hydration states, are characterized, and the data are fitted to a Cole–Cole model. The complex dielectric permittivity for all prepared solutions and mixtures is studied in the range of 1–20 GHz, at temperature of 23 °C, with ionic concentrations in the range of 0.01–1.7 mol/L.

This study evaluated the effectiveness of alumina fabricated by atomic layer deposition (ALD) as a protective coating for silver articles against the corrosion caused by body contact. An artificial sweat solution was used to simulate body contact. ALD alumina layers of varying thicknesses ranging from 20 to 80 nm were deposited on sputtered silver samples. The stability of the protective layer was evaluated by immersing the coated samples in the artificial sweat solution at 25 and 35 °C for 24 h. We confirmed that a sufficiently thick layer of ALD alumina is effective in protecting the shape and light reflectance of the underlying silver, whereas the uncoated bare silver is severely degraded by the artificial sweat solution. Inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy were used for in-depth analyses of the chemical stability of the ALD-coated silver samples after immersion in the sweat solution. [ABSTRACT FROM AUTHOR]

This paper presents the results of an investigation of the water and peloid, of the element enrichment factor of the mud and the element mobility that occurs between artificial sweat and peloid from Buuntsagaan lake in the province of Bayankhongor, Mongolia. The water is of the chloride-magnesium type containing dark grey clay. The latter consists of 53.41 % of moisture and 2.43 % organic carbon (Corg). Its density is equal to 1.58 g cm-3, while its рН value amounts to 7.83. These results show that the peloid of Buuntsagaan lake is a hydrogen sulfide silt according to the international classification of the medicinal clay and fulfills the requirements of balneotherapy. It is classified as poly-mineral clay on the ground of the mineral composition of predominating phyllo- and tectosilicates. The enrichment factor is the main performance which indicates the source of pollution. We have defined elements in the clay that are vital for the human body from pharmacological point of view and take part in organisms fermentation (Sr, Cr, Cu, Zn, Co and Ni) along with some poisonous one (As, Pb and V). The enrichment factor EF of As, is equal to 3.11 - 3.27, while that of the elements Co, Cr, Cu, Ni, Pb, V, Zn and Sr is in the range of 0 < EF < 1.20. The elements content and their accumulation in the peloid are related to the minerals contained and their geochemistry properties. When peloid and artificial sweat interact, elements like Na, Mg, Ca, K and Sr are leached in high amounts from the peloid. Low concentrations of V (0.005 μg g-1), Mn (0.025 μg g-1), Fe (0.125 μg g-1), Ga (0.019 μg g-1), Se (0.016μg g-1) and Sb (0.012 μg g-1) are observe in the course of the same process. The mobility of Li, Cr, Zn, As and Ba from the peloid to the artificial sweat is also low. It refers to 0.009 μg g-1- 0.042 μg g-1. [ABSTRACT FROM AUTHOR]

Increasing use of nanomaterials for consumer products has induced growing concerns on their adverse effects on human health and the environment. To assess the environmental and human health risks of these nanoproducts, it is essential to identify physicochemical forms and quantify the amount of nanomaterials released from nanoproducts upon exposure to various environments. In this study, we have investigated the release assessment of nano-Ag textile products in terms of the total Ag content, and the distribution of Ag materials in the textile and the surrounding environment. The results suggest that the release of Ag nanomaterials from consumer products is less dependent on the total Ag content in the consumer product and depends significantly on the manufacturing processes of the consumer products as well as exposure environment. Based on these experimental results and a simple exposure model, the highest total exposure to particulate/dissolved Ag per use during sweating (1 h) was estimated to be 0.81/2.03 μg Ag/kg body weight with a standard body weight of 77 kg for a male. These results are fairly minimal human exposure and suggest that textiles containing Ag nanomaterials may be less of a concern in terms of human exposure to Ag nanomaterials. [ABSTRACT FROM PUBLISHER]

This study compares the effect of colloidal silver nanoparticles and commercial RUCO-BAC AGP agent with silver chloride as an active component on antibacterial activity of dyed cotton fabrics. Cotton fabrics were dyed with vat dyes Bezanthren olive T and Bezanthren grey FFB. Antibacterial activity of silver loaded dyed cotton fabrics was tested against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacterium Escherichia coli. Unlike RUCO-BAC AGP synthesized silver nanoparticles deposited onto dyed cotton fabrics provided maximum bacteria reduction independently of applied dye. The stability of modified cotton fabrics was analyzed in artificial sweat at pH 5.5 and 8.0. Approximately the same amount of silver was released from differently modified cotton fabrics in artificial sweat. Larger amount of silver was released in the sweat at pH 8.0.

This work illustrates the potentiality of a mixed array merging the Nanowire and thin film metal oxide technologies to develop an electronic nose as a tool to monitor the human skin and food pathogen microbiota. Nanowire and thin film sensors have been fabricated, characterized and then integrated together to develop a hybrid device that can enhance the sensing performance. Different blends of microorganisms grown in artificial sweat have been tested. Classical techniques, like GC–MS (Gas Chromatography–Mass Spectrometry) with SPME (Solid Phase Micro Extraction) have been employed in parallel, in order to have a multidisciplinary approach and a consistent data set. The obtained results show the potentiality of the proposed electronic nose to discriminate between the different blends of microorganisms and to follow up microbiota growth inside the blends. [ABSTRACT FROM AUTHOR]

Metal release from materials immersed in artificial sweat can function as a measure of potential skin exposure. Several artificial sweat models exist that, to various degree, mimic realistic conditions. Study objective was to evaluate metal release from previously examined and well characterized materials in two different artificial sweat solutions; a comprehensive sweat model intended for use within research, based on the composition of human sweat; and the artificial sweat, EN1811, intended for testing compliance with the nickel restriction in REACH. The aim was to better understand whether there are advantages using either of the sweat solutions in bio-elution testing of materials. Metal release in two different artificial sweat solutions was compared for discs of a white gold alloy and two hard metals, and a rock drilling insert of tungsten carbide at 1 h, 24 h, 1 week and 1 month. The released amount of metal was analysed by means of inductively coupled plasma mass spectrometry. Similar levels of released metals were measured from test materials in the two different artificial sweat solutions. For purposes in relation to legislations, it was concluded that a metal release test using a simple artificial sweat composition may provide results that sufficiently indicate the degree of metal release at skin contact. [ABSTRACT FROM AUTHOR]

This work reports the effects of annealing on the material properties and sweat sensing behavior of nanostructured CuO-based films. CuO films were grown on glass substrates via SILAR (Successive Ionic Layer Adsorption and Reaction) method. Films were annealed at 200 °C and 400 °C in ambient air for 45 min. Scanning electron microscopy analysis confirmed the plate-like morphology of CuO nanostructures with average plate thickness increasing from 30 nm to 70 nm with increasing annealing temperature. X-ray diffraction studies of the films revealed that the average crystallite sizes were around 17–22 nm. The bandgap values were calculated from the UV–visible absorbance spectrum and it was determined that the annealing process lowered the bandgap valued from 1.46 eV to 1.38 eV suggesting that the resistivity would also decrease. The prospect of sweat electrolyte sensing properties of CuO films was studied by drop cast application of different concentrations of artificial sweat solutions. We found that annealing process increases the sensitivity of sweat electrolyte level detection for particularly low concentration artificial sweat solutions. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we investigated how tannic acid (TA) protects the skin from inflammation caused by external irritation. The effects of TA were evaluated using a mouse 12‐O‐tetradecanoylphorbol 13‐acetate (TPA)‐induced skin inflammation model and a reconstructed human epidermal model. We then used Lucifer Yellow for visual confirmation of TA's suppression effect at the stratum corneum (SC) surface. TA treatment of the skin prevented Lucifer Yellow from permeating the skin. This result suggests that TA acts as a barrier against external stimulants such as TPA and artificial sweat on the SC surface. [ABSTRACT FROM AUTHOR]

In this study, un-doped, Na-doped, and K-doped nanostructured CuO films were successfully synthesized by the successive ionic layer adsorption and reaction (SILAR) technique and then characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and current–voltage ( I – V ) measurements. Structural properties of the CuO films were affected from doping. The XRD pattern indicates the formation of polycrystalline CuO films with no secondary phases. Furthermore, doping affected the crystal structure of the samples. The optimum conductivity values for both Na and K were obtained at 4 M% doping concentrations. The comparative hydration level sensing properties of the un-doped, Na-doped, and K-doped CuO nanoparticles were also investigated. A significant enhancement in hydration level sensing properties was observed for both 4 M% Na and K-doped CuO films for all concentration levels. Detailed discussions were reported in the study regarding atomic radii, crystalline structure, and conductivity. [ABSTRACT FROM AUTHOR]

In this work is illustrated the potentiality use of a Nanowire (Nw) MOS sensor array to be use as tool to monitor the human skin microbiota in order to identify quantitative and qualitative changes. Tree different blends of microorganisms grown in artificial sweat have been tested. Classical techniques, like GC-MS with SPME, have been performed as well, in order to have a multidisciplinary approach and consistent data set. The obtained results show the ability of the NW technology to discriminate between the different blends of microorganisms and to follow up the development of the growth inside the blends during the analysis. The previous results have been confirmed by GC-MS with SPME. [ABSTRACT FROM AUTHOR]

In order to study fingerprinting in the field of forensic science, it is very important to have two or more latent fingerprints with identical chemical composition and intensity. However, it is impossible to obtain identical fingerprints, in reality, because fingerprinting comes out slightly differently every time. A previous research study had proposed an artificial fingerprint creation method in which inkjet ink was replaced with amino acids and sodium chloride solution: the components of human sweat. But, this method had some drawbacks: divalent cations were not added while formulating the artificial sweat solution, and diluted solutions were used for creating weakly deposited latent fingerprint. In this study, a method was developed for overcoming the drawbacks of the methods used in the previous study. Several divalent cations were added in this study because the amino acid-ninhydrin (or some of its analogues) complex is known to react with divalent cations to produce a photoluminescent product; and, similarly, the amino acid-1,2-indanedione complex is known to be catalyzed by a small amount of zinc ions to produce a highly photoluminescent product. Also, in this study, a new technique was developed which enables to adjust the intensity when printing the latent fingerprint patterns. In this method, image processing software is used to control the intensity of the master fingerprint patterns, which adjusts the printing intensity of the latent fingerprints. This new method opened the way to produce a more realistic artificial fingerprint in various strengths with one artificial sweat working solution. [ABSTRACT FROM AUTHOR]

Background The existing EU nickel restriction does not sufficiently protect the population from skin exposure to nickel. Better understanding is needed of the extent to which short and frequent contact with nickel-releasing items contributes to nickel deposition on skin. Objectives To quantify nickel skin exposure from short and frequent contact with nickel-releasing materials. Materials/methods Sequences of short contact events were assessed in (i) touch tests for measurement of nickel skin dose, (ii) wipe tests to similarly quantify the nickel release during a touch, and (iii) immersion tests in artificial sweat, for nickel-containing alloys and pure nickel. Results Nickel skin doses from a single touch were 0.024-4.7 µg/cm2 for all materials. Touching or wiping five untouched surfaces resulted in more accumulated nickel than five repeated touches of the same surface. The released amounts of nickel were generally lower at immersion, but increased with the number of repeated immersion periods. Conclusions Nickel skin doses were quantified after one single touch for all study materials. Touch tests, and potentially wipe tests as a proxy for skin dose measurements, are preferred to immersion tests for the assessment of short and frequent skin contact with nickel. [ABSTRACT FROM AUTHOR]

Brass samples were controllably tarnished using the thioacetamide accelerated corrosion (ISO 4538:1995) and synthetic sweat (ISO 3160-2:2003) methods. Spectrophotometry, energy dispersive X-ray spectroscopy (EDX) and electrochemical impedance spectroscopy (EIS) were performed on samples tarnished for set exposure times over seven days. Synthetic sweat produced a loose surface corrosion layer, which limited the use of EIS and spectrophotometry, but for the thioacetamide method both measurements produced a continuous change over the time period. EDX was able to observe a continuous change in the surface layer chemistry for both methods over the whole timescale and represents the best characterisation method to establish an equivalent tarnish timeline against which anti-tarnish treated samples can be compared. The current study was conducted using brass, however the method can be used for quantifying tarnish on other metallic systems. [ABSTRACT FROM AUTHOR]

A new method of sweat sensing based on nanostructured Copper Oxide (CuO) films is presented. Films were developed by the Successive Ionic Layer Adsorption and Reaction (SILAR) method. The morphological, structural and electrical properties of the CuO films were investigated by scanning electron microscopy, X-ray diffraction analysis, and room temperature current–voltage measurements, respectively. We doped CuO films with artificial sweat during the film growth process. We also drop cast the surface of the intrinsic CuO films with artificial sweat to investigate the effect of partial doping. Our results showed that partial doping indeed gave results consistent with those of actual doping. The resistivity of the partially doped films was decreased with increasing artificial sweat concentrations. [ABSTRACT FROM AUTHOR]

Background Many daily contacts with metallic items are short and repetitive, and result in metal release; material, sweat, friction and wear may all be important. Objectives To study cobalt release and skin deposition as a result of many short and repetitive contacts with two cobalt-containing materials. Materials/methods Study participants (n = 5) handled two types of hard metal disc ( Co 6% and Co 15% Cr 0.6%) for 30 min. Deposited cobalt skin doses were measured with acid wipe sampling and chemical analysis. Cobalt release from the hard metal discs in artificial sweat was measured under conditions simulating those present during the handling of discs. Results Average cobalt skin doses from discs containing 6% Co and 15% Co 0.6% Cr were 1.1 µg/cm2 [standard deviation ( SD) 0.4 µg/cm2] and 0.7 µg/cm2 ( SD 0.5 µg/cm2), respectively. More cobalt was released from hard metal discs containing 6% Co [11.4 µg/cm2 ( SD 1.2 µg/cm2)] than from discs containing 15% Co 0.6% Cr [4.8 µg/cm2 ( SD 0.6 µg/cm2)]. 10% to 15% of the potentially available cobalt was deposited on the skin during handling. Conclusions It is likely that the cobalt deposited as a result of short and repetitive contact with hard metals may cause harm. Research regarding cobalt exposure, metal release and the deposition of skin-sensitizing metals resulting from short and repetitive contact is needed for a better understanding of the allergy risk. [ABSTRACT FROM AUTHOR]

The European Union restricted the amount of hexavalent chromium (Cr(VI)) in leather in 2015, but skin allergy cases due to Cr-tanned leather are not declining. Standardized extraction methods have been criticized to both over- and underestimate the expected amount of bioavailable Cr(VI) in leather. This study aims to evaluate the ability of four extraction solutions to reduce or preserve Cr(VI): artificial sweat solutions (ASWs) of pH 4.7, 6.5, and 8.0, and phosphate buffer (PB) of pH 8.0. This was investigated by incubating each solution with added Cr(VI) as a function of time, and then measuring the recovered Cr(VI). All solutions, especially PB, preserved Cr(VI) for 24 h. These solutions were also pre-exposed to Cr-free vegetable-tanned leather (VTL) before incubation with Cr(VI). Released vegetable tannin species strongly reduced Cr(VI), with up to 4000 μg/L added Cr(VI) reduced in all solutions after 24 h. However, after 1 h, Cr(VI) was still detectable in extraction solutions at pH 6.5 and above. The reduction of Cr(VI) in relevant extraction solutions is hence a process dependent on time, pH, and the presence of co-released leather species. All extraction solutions, but least PB, have the potential to underestimate any Cr(VI) present on the surface of leather. [Display omitted] • Cr(VI) measured as function of incubation time in different solutions. • Artificial sweat solutions and deaerated phosphate buffer tested. • All solutions (pH 4.7–8.0) preserved added Cr(VI) up to 24 h. • Deaerated phosphate buffer at pH 8.0 had the lowest reduction of Cr(VI). • Incubation with Cr-free leather reduced Cr(VI) with time and decreasing pH. [ABSTRACT FROM AUTHOR]

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Flow injection cold vapor atomic absorption spectrometry (FI-CVAAS) was used for determination of cadmium in high salt matrices such as dialysis concentrates and textile leach solutions. The parameters such as acidity, concentration of reducing agent, reaction coil length, and carrier gas flow rate were investigated to obtain the best sensitivity. No significant background signal was observed even at high salt concentrations. Under the optimized conditions the limit of detection value (3s b m-1, where sb is the standard deviation of the blank signals and m is the slope of the calibration graph) was found to be 0.05 ng mL-1 for an injection volume of 250 µL and the precision in terms of relative standard deviation was 3.2% using 11 consecutive measurements of 0.5 ng mL-1 standard. The standard addition method was used for quantitation. The accuracy of the method was tested using ETAAS as a comparison method and a certified reference material (Waste Water EU-L-1). In both cases, the results were in good agreement at 95% confidence level. The concentrations of cadmium in textile product leach solutions were found to be below the limit value assigned by Oeko-Tex standards. [ABSTRACT FROM AUTHOR]

Corrosion properties of thin layers of a copper-tin-zinc-indium alloy ("white bronze") were investigated in an artificial sweat solution indicating poor resistance properties. The coating degraded via pitting, generalized, and crevice corrosion, as evidenced by scanning electron microscopy-energy-dispersive x-ray analysis (SEM-EDX) investigation. The corrosion mechanism was investigated in situ by means of electrochemical impedance spectroscopy (EIS), and ex situ by x-ray photoelectron spectroscopy (XPS). These combined results demonstrate that the key point of the corrosion failure is the removal of the passive In-Sn oxides. [ABSTRACT FROM AUTHOR]