Okpozo Paul, Dwivedi Yashashchandra, Huo Dehong, Pancholi Ketan
School of Engineering, Sir Ian Wood Building, Robert Gordon University Garthdee Aberdeen AB10 7GJ UK
Physics Department, National Institute of Technology Kurukshetra Kurukshetra 136119 India.
RSC Adv. 2023 Aug 10;13(34):23955-23966. doi: 10.1039/d3ra01369c. eCollection 2023 Aug 4.
Molecular vibration signals were amplified by the gold strip gratings as a result of grating resonances and nearby electric field hotspots. Colloidal gold island films exhibit similar enhancement; however, the uneven geometrical characteristics of these films restrict the tunability of the vibrational enhancement. Infrared absorption is enhanced by regular metallic patterns such as arrays of strips fabricated using a top-down approach such as nanolithography, although this technology is expensive and difficult. The significant infrared absorption may serve as tuneable antenna sensitization to improve the sensor performance. In this article, we present a simple one-step process for fabricating optically sensitive ordered arrays of a gold nanoparticle ferrofluid emulsion in polyvinyl alcohol (PVA) using a magnetic field-directed and spin-coating self-assembly (MDSCSA) process. Techniques such as UV-visible absorption, scanning electron microscopy, and grazing-angle infrared spectroscopy were used to evaluate various parameters associated with the nanostructures. Unlike the gold strips, the chain-like features in the iron oxide nanoparticle arrays were discontinuous. The fabricated chain-like ordered arrays have been shown to increase the local field to enhance the infrared absorption corresponding to the symmetric vibration of the -CH (2918 cm) group present in PVA by ∼667% at a 45° grazing angle, as the chain thickness (CT) increased by 178%. This scalable and simple method can potentially generate low-cost patterns for antenna sensitisation.
由于光栅共振和附近的电场热点，分子振动信号被金带光栅放大。胶体金岛膜表现出类似的增强效果；然而，这些膜不均匀的几何特征限制了振动增强的可调性。红外吸收通过规则的金属图案增强，例如使用自上而下的方法（如纳米光刻）制造的条带阵列，尽管这种技术昂贵且困难。显著的红外吸收可作为可调谐天线敏化来提高传感器性能。在本文中，我们提出了一种简单的一步法，使用磁场导向和旋涂自组装（MDSCSA）工艺在聚乙烯醇（PVA）中制备金纳米颗粒铁磁流体乳液的光学敏感有序阵列。使用紫外可见吸收、扫描电子显微镜和掠角红外光谱等技术来评估与纳米结构相关的各种参数。与金带不同，氧化铁纳米颗粒阵列中的链状特征是不连续的。所制备的链状有序阵列已被证明，在45°掠角下，随着链厚度（CT）增加178%，对应于PVA中-CH（2918 cm）基团对称振动的红外吸收增强了约667%。这种可扩展且简单的方法有可能为天线敏化生成低成本图案。
