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Concave gold nanocubes are viable optical nanoprobes for the determination of nitrite ions. Herein, a novel approach was developed, based on the measurement of localized surface plasmon resonance absorption. The addition of nitrite ions selectively induced the etching of concave gold nanocubes, abrading the sharp vertices to spherical corners, which resulted in blue-shifted absorption accompanied by a color change from sapphire blue to light violet. The mechanism of selective etching of concave gold nanocube tips was elucidated by using X-ray photoelectron spectroscopy and atom probe tomography. The optimized detection of NO2− via the concave gold nanocube-based probe occurred at pH 3.0 and in 20 mM NaCl concentration at 40 °C. The absorption ratios (A550 nm/A640 nm) were proportional to the NO2− concentrations in the range 0.0–30 μM, with a detection limit of 38 nM (limit of quantitation of 0.12 μM and precision of 2.7%) in tap water. The highly selective and sensitive colorimetric assay has been successfully applied to monitor the nitrite ion concentrations in spiked tap water, pond water, commercial ham, and sausage samples. [ABSTRACT FROM AUTHOR]

Lacquer has been used in Asian countries for thousands of years as a natural coating material owing to its durable, adhesive, decorative, and protective properties. Protection and restoration of lacquer-coated cultural remains has become an important subject, and identification of the lacquer types in old lacquer-wares has also become very important for conservation and restoration research. This paper provides identification of several molecular species of vegetal-source Asian lacquers with the aim of providing a methodology for application in the field of cultural heritage. Several chemical markers of the vegetal species in Asian lacquers were identified using a methodology consistent with the sampling restrictions required for cultural-heritage objects. Surface analytical methods such as time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy were used to characterize Korean, Chinese, and Vietnamese lacquers; avoiding time-consuming and destructive extraction processes. These ToF-SIMS results provided the structural characterization of a series of catechol derivatives. The ToF-SIMS spectra of Rhus vernicifera from Korea and China, and Rhus succedanea from Vietnam indicated a series of urushiol and laccol repeat units, respectively, in the mass range of m/z 0-1800. Because of its sensitivity, specificity, and speed of analysis, the ToF-SIMS technique can be used to investigate cultural lacquer-coated treasures as well as to discriminate among different Asian lacquer coatings or binding mediums for the conservation or restoration of lacquer-ware. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Analytical identification of dyes in excavated textiles is an indispensable task for conservation research and restoration of ancient remains. However, excavated textiles have changed in color because of the burial environment and their centuries of burial; also, the color gradually fades after excavation. Furthermore, the low amount and limited availability of samples make it extremely difficult to identify the dyes. Therefore, in this study, non-destructive analytical instruments such as time-of-flight secondary ion mass spectrometry (TOF-SIMS), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were used for dye detection, and analysis results are compared. In order to compare a dye to another dye, standard samples of dyed silk were prepared using dye compounds such as curcumin, berberine, quercetin, and indigo. These samples were then analyzed with TOF-SIMS and FTIR. After the methodology to determine the dyes in the textiles was established, surface analytical techniques were also performed on three ancient textiles coming from 18th century Joseon Dynasty tombs. From the TOF-SIMS and the FTIR spectra, indigo was detected on the blue textile, and indigo and berberine were detected on the green and brown textiles. The results suggest that TOF-SIMS and FTIR are efficient and complementary non-destructive techniques for the characterization of excavated fabrics. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Polycrystalline copper-indium-gallium-diselenide (CIGS) is used as an absorber in thin-film solar cells because of its appropriate band gap and high absorption coefficient for solar radiation. Many research groups have determined the CIGS compositions related to solar cell efficiency. In this work, three different Cu(In,Ga)Se2 thin films were prepared on molybdenum back contacts deposited on soda-lime glass substrates via a three-stage evaporation or, alternatively, a two-step selenized process. Surface analyses via AES, XPS, and SIMS were used to characterize the CIGS thin films and compare their depth profiles. TheMCs+ clusters were detected to improve the quantification of major compositions in the CIGS thin films while suppressing the matrix effect in the SIMS depth profiles. The compositional distribution in the MCs+-SIMS was in good agreement with the AES and XPS depth profiles. The MCs+-SIMS results proved more quantitatively accurate than those from the elemental SIMS while comparing to ICP-AES data. [ABSTRACT FROM AUTHOR]

The cover image, by Jihye Lee et al., is based on the Research Article Investigation of Asian lacquer films using ToF‐SIMS and complementary analytical techniques, DOI 10.1002/sia.6181. [ABSTRACT FROM AUTHOR]

We investigated the growth mechanism of SiO x N y films deposited via plasma-enhanced atomic layer deposition at low temperatures (100–300 °C) using a tetraisocyanate silane (Si(NCO) 4) precursor and N 2 plasma. By using tetraisocyanate silane, which does not contain hydrogen, we were able to deposit SiO x N y with notably less hydrogen, around 3–5%, compared to using silicon precursors that contain hydrogen. Additionally, the precursor ligands, including oxygen, react with surface amine groups (-NH 2) to form Si – N –O bonds. Therefore, by understanding the adsorption mechanism of the precursor and controlling the temperature that can affect the bond formation, we can successfully produce SiO x N y films without any oxidizing source. We utilized density functional theory to explore the adsorption mechanism during the deposition of SiO x N y films and proposed a possible adsorption pathway of the precursors and by-products on the surface. We also employed various characterization techniques, such as spectroscopic ellipsometry, X-ray photoelectron spectroscopy, X-ray reflectometry, secondary ion mass spectroscopy, and current-electric field and capacitance-voltage analyses to establish correlations between the composition and dielectric properties of the thin films. Increasing the deposition temperature results in an increased presence of stronger and more stable Si –N bonds compared to Si –O and O –N bonds. As a result, the dielectric constant of the SiO x N y film increased from 5.8 to 7.4, while the leakage current density decreased from 1.52 × 10−8 A/cm2 to 8.56 × 10−10 A/cm2. Additionally, the counterclockwise hysteresis decreased from 0.16 V to 0.07 V as the amount of hydrogen in the SiO x N y film decreased. This can be interpreted as a reduction in hydrogen impurities, which act as charge trapping sites within the film, leading to a decrease in hysteresis with increasing temperature. [ABSTRACT FROM AUTHOR]

Incurvate gold nanohexahedrons (AuNHs) are feasible colorimetric probes for the monitoring of chlorite (ClO 2 −) ions. In this study, incurvate AuNHs were found to respond to ClO 2 − ions selectively, and the addition of ClO 2 − ions to water samples induced selectively the etching of incurvate AuNHs, eroding the sharp apexes to rounded edges, which brought in hypsochromic shift absorption attended by a color alternation from cobalt blue to violet pink. The process of etching of incurvate AuNH vertices was characterized using X-ray photoelectron spectroscopy and atom probe tomography. ClO 2 − ions were successfully detected using the incurvate AuNH-based probe at pH 2.0 and 25 °C with 20 mM NaCl. The A 563 nm /A 631 nm were linear in proportion to the ClO 2 − concentrations with two different slopes in the ranges 0.00–0.06 μM and 0.075–0.15 μM, and detection limits of 3.03 and 3.27 nM in tap water and waste water, respectively. The hypersensitive and selective optical assay reported herein has been excellently implemented to determine ClO 2 − concentrations in spiked tap water, waste water, Clorox cleaning solution, and disinfecting wipes. [Display omitted] • Incurvate AuNHs were synthesized as viable optical nanoprobe of ClO 2 − ions. • ClO 2 − ions induced selectively the etching for the sharp vertices of AuNHs. • The etching of AuNHs resulted in a color change from cobalt blue to violet pink. • The AuNH probe of ClO 2 − was optimized at pH 2, 25 °C, and 20 mM NaCl concentration. • The AuNH probe showed a LOD of 3.03 nM ClO 2 − in tap water. [ABSTRACT FROM AUTHOR]

A tetraphenylethene (TPE) derivative was designed and synthesized upon conjugation with bis(thiophen-2-ylmethyl) amine (BTA) containing a mercury-binding moiety and further characterized by using Nuclear magnetic resonance (NMR), LC-MS, UV–Vis, and fluorescence spectroscopic methods. The resulting TPE-BTA exhibited comprehensive aggregation-induced emission while expressing a high quantum yield and emission intensity at 70% water fraction. The probe exhibited a good photochromic effect with a Stokes shift of 178 nm, and the emission intensity at 550 nm increased considerably with the color turning from dark green to bright green under a UV lamp upon the addition of 5 μM Hg2+. The lowest-energy conformation of the probe showed that two thiophene rings were perpendicular to the phenyl ring, while two BTA molecules were situated in a staggered form to each other. The sulfur and nitrogen atoms present in TPE-BTA were coordinated to the Hg2+ ion, and these binding sites were confirmed by the NMR parameters, X-ray photoelectron spectroscopy signals, and structural calculations. The binding of Hg2+ to TPE-BTA was believed to restrict the intramolecular motion of TPE-BTA, thus inducing it to shine brighter according to the unique aggregation-induced emission effect. The concentration of Hg2+ was determined based on the enhancement of the emission intensity, and the present probe showed an extremely high sensitivity with a limit of detection of 10.5 nM. Furthermore, TPE-BTA enabled selective detection of Hg2+ even in the presence of a 1000-fold excess of other interfering metal ions. The proposed method was successfully employed to determine Hg2+ in living HeLa cells and real water samples. Image 1 • A tetraphenylethene derivative (TPE-BTA) was designed and synthesized. • The molecular structures of TPE-BTA and TPE-BTA-2Hg2+ were proposed theoretically. • TPE-BTA showed highly sensitive and selective response for recognition of Hg2+. • The binding of Hg2+ to TPE-BTA induced it to shine brighter by the AIE effect. • TPE-BTA can be utilized as bioimaging reagent for Hg2+ in living HeLa cells. [ABSTRACT FROM AUTHOR]