We demonstrate tin (Sn) nanowires growth enhanced by Selenium (Se) atoms via physical vapor transport (PVT) method. The Raman spectroscopy, X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy show that Sn nanowires are synthesized with a large quantity, good quality and high purity of Sn. The growth of Sn nanowires is attributed to Solid–Vapor–Liquid mechanism. The effects of gold nanoparticles catalyst, Si substrate, and Se atoms on Sn nanowires growth are discussed in detail. We find that Se atom plays a key role in the growth of Sn nanowires. The gaseous Sn atoms are absorbed by the eutectic alloy droplets of Se–Au at first. Then Sn atoms precipitate at the liquid–solid phase interface due to a supersaturated solution and form a one-dimensional nanostructure. In all, this PVT method could provide a simple and quick way to synthesize monocrystalline Sn nanowires with an advantage in both quality and quantity. The optical transmittance of Sn nanowires thin film with 2 μm 2 density approaches 85–90% in visible wavelength. Therefore, the Sn nanowires thin film can be applied to transparent electrode along with their metallic property.
A Se site targeted-two circles antioxidant of polyphenols EGCG and genistein in glutathione peroxidase 4 (GPx4)–like catalytic peroxide H 2 O 2 and cumene hydroperoxide degradation was demonstrated by surface-enhanced Raman scattering (SERS). Se atom's active center is presenting a ‘low-oxidation’ and a ‘high-oxidation’ catalytic cycle. The former is oxidized to selenenic acid (SeO − ) with a Raman bond at 619/ 610 cm −1 assigned to the νO − Se by the hydroperoxide substrate at 544/ 551 cm −1 assigned to ωHSeC decreased. Under oxidative stress, the enzyme shifted to ‘high-oxidation’ catalytic cycle, in which GPx4 shuttles between R-SeO − and R-SeOO − with a Raman intensity of bond at 840/ 860 cm −1 assigned to νO Se. EGCG could act as a reducing agent both in H 2 O 2 and Cu-OOH degradation, while, genistein can only reduce Cu-OOH, because it binds more readily to the selenium site in GPx4 than EGCG with a closer proximity, therefore may affect its simultaneous binding to coenzymes.
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