Satya Bharati Moram Sree, Chandu Byram, Rao S Venugopal
Advanced Centre for Research in High Energy Materials (ACRHEM), University of Hyderabad Prof. C. R. Rao Road Hyderabad 500046 Telangana India
RSC Adv. 2019 Jan 11;9(3):1517-1525. doi: 10.1039/c8ra08462a. eCollection 2019 Jan 9.
Herein we demonstrate the synthesis of Ag-Cu alloy NPs through a consecutive two-step process; laser ablation followed by laser irradiation. Initially, pure Ag and Cu NPs were produced individually using the laser ablation in liquid technique (with ∼50 femtosecond pulses at 800 nm) which was followed by laser irradiation of the mixed Ag and Cu NPs in equal volume. These Ag, Cu, and Ag-Cu NPs were characterised by UV-visible absorption, HRTEM and XRD techniques. The alloy formation was confirmed by the presence of a single surface plasmon resonance peak in absorption spectra and elemental mapping using FESEM techniques. Furthermore, the results from surface enhanced Raman scattering (SERS) studies performed for the methylene blue (MB) molecule suggested that Ag-Cu alloy NPs demonstrate a higher enhancement factor (EF) compared to pure Ag/Cu NPs. Additionally, SERS studies of Ag-Cu alloy NPs were implemented for the detection of explosive molecules such as picric acid (PA - 5 μM), ammonium nitrate (AN - 5 μM) and the dye molecule methylene blue (MB - 5 nM). These alloy NPs exhibited superiority in the detection of various analyte molecules with good reproducibility and high sensitivity with EFs in the range of 10 to 10.
在此，我们展示了通过连续两步法合成Ag-Cu合金纳米颗粒；先进行激光烧蚀，然后进行激光辐照。最初，使用液体中的激光烧蚀技术（在800nm处使用约50飞秒脉冲）分别制备纯Ag和Cu纳米颗粒，随后对等量混合的Ag和Cu纳米颗粒进行激光辐照。通过紫外可见吸收、高分辨透射电子显微镜和X射线衍射技术对这些Ag、Cu和Ag-Cu纳米颗粒进行了表征。通过吸收光谱中单个表面等离子体共振峰的存在以及使用场发射扫描电子显微镜技术进行的元素映射证实了合金的形成。此外，对亚甲基蓝（MB）分子进行的表面增强拉曼散射（SERS）研究结果表明，与纯Ag/Cu纳米颗粒相比，Ag-Cu合金纳米颗粒表现出更高的增强因子（EF）。此外，对Ag-Cu合金纳米颗粒进行了SERS研究，用于检测苦味酸（PA - 5μM）、硝酸铵（AN - 5μM）等爆炸物分子以及染料分子亚甲基蓝（MB - 5 nM）。这些合金纳米颗粒在检测各种分析物分子方面表现出优势，具有良好的重现性和高灵敏度，增强因子在10至10范围内。
