The Emission Mechanism of Gold Nanoclusters Capped with 11-Mercaptoundecanoic Acid, and the Detection of Methanol in Adulterated Wine Model
| Autor: | Ming Wei, Lijun Wang, Dan Luo, Ye Tian, Yuankai Hong, Yinlin Sha |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Technology
Photoluminescence Materials science Analytical chemistry ligand Article Nanoclusters chemistry.chemical_compound size effect Etching emission mechanism General Materials Science Photoluminescence excitation Absorption (electromagnetic radiation) Microscopy QC120-168.85 QH201-278.5 Engineering (General). Civil engineering (General) Isotropic etching TK1-9971 source of absorption chemistry Descriptive and experimental mechanics gold nanocluster Methanol Electrical engineering. Electronics. Nuclear engineering TA1-2040 Excitation |
| Zdroj: | Materials, Vol 14, Iss 6342, p 6342 (2021) Materials Volume 14 Issue 21 |
| ISSN: | 1996-1944 |
| Popis: | The absorption and emission mechanisms of gold nanoclusters (AuNCs) have yet to be understood. In this article, 11-Mercaptoundecanoic acid (MUA) capped AuNCs (AuNC@MUA) were synthesized using the chemical etching method. Compared with MUA, AuNC@MUA had three obvious absorption peaks at 280 nm, 360 nm, and 390 nm its photoluminescence excitation (PLE) peak and photoluminescence (PL) peak were located at 285 nm and 600 nm, respectively. The AuNC@MUA was hardly emissive when 360 nm and 390 nm were chosen as excitation wavelengths. The extremely large stokes-shift (> 300 nm), and the mismatch between the excitation peaks and absorption peaks of AuNC@MUA, make it a particularly suitable model for studying the emission mechanism. When the ligands were partially removed by a small amount of sodium hypochlorite (NaClO) solution, the absorption peak showed a remarkable rise at 288 nm and declines at 360 nm and 390 nm. These experimental results illustrated that the absorption peak at 288 nm was mainly from metal-to-metal charge transfer (MMCT), while the absorption peaks at 360 nm and 390 nm were mainly from ligand-to-metal charge transfer (LMCT). The PLE peak coincided with the former absorption peak, which implied that the emission of the AuNC@MUA was originally from MMCT. It was also interesting that the emission mechanism could be switched to LMCT from MMCT by decreasing the size of the nanoclusters using 16-mercaptohexadecanoic acid (MHA), which possesses a stronger etching ability. Moreover, due to the different PL intensities of AuNC@MUA in methanol, ethanol, and water, it has been successfully applied in detecting methanol in adulterated wine models (methanol-ethanol-water mixtures). |
| Databáze: | OpenAIRE |
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