Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
Biosensors (Basel). 2019 Sep 19;9(3):111. doi: 10.3390/bios9030111.
We show a new type of elastic surface-enhanced Raman spectroscopy (SERS) platform made of poly(ethylene terephthalate) (PET) covered with a layer of indium tin oxide (ITO). This composite is subjected to dielectric barrier discharge (DBD) that develops the active surface of the PET/ITO foil. To enhance the Raman signal, a modified composite was covered with a thin layer of silver using the physical vapor deposition (PVD) technique. The SERS platform was used for measurements of -mercaptobenzoic acid (-MBA) and popular pesticides, i.e., Thiram and Carbaryl. The detection and identification of pesticides on the surface of fruits and vegetables is a crucial issue due to extensive use of those chemical substances for plant fungicide and insecticide protection. Therefore, the developed PET/ITO/Ag SERS platform was dedicated to quantitative analysis of selected pesticides, i.e., Thiram and Carbaryl from fruits. The presented SERS platform exhibits excellent enhancement and reproducibility of the Raman signal, which enables the trace analysis of these pesticides in the range up to their maximum residues limit. Based on the constructed calibration curves, the pesticide concentrations from the skin of apples was estimated as 2.5 µg/mL and 0.012 µg/mL for Thiram and Carbaryl, respectively. Additionally, the PET/ITO/Ag SERS platform satisfies other spectroscopic properties required for trace pesticide analysis e.g., ease, cost-effective method of preparation, and specially designed physical properties, especially flexibility and transparency, that broaden the sampling versatility to irregular surfaces.
我们展示了一种新型的弹性表面增强拉曼光谱（SERS）平台，由聚对苯二甲酸乙二醇酯（PET）覆盖一层氧化铟锡（ITO）组成。这种复合材料经过介质阻挡放电（DBD）处理，开发了 PET/ITO 箔的活性表面。为了增强拉曼信号，使用物理气相沉积（PVD）技术在改性复合材料上覆盖一层薄薄的银。SERS 平台用于测量 -巯基苯甲酸（-MBA）和常见的农药，即福美双和carbaryl。由于广泛使用这些化学物质来保护植物的杀菌剂和杀虫剂，因此在水果和蔬菜表面检测和识别农药是一个至关重要的问题。因此，开发的 PET/ITO/Ag SERS 平台专门用于定量分析选定的农药，即水果中的福美双和carbaryl。所提出的 SERS 平台表现出优异的拉曼信号增强和重现性，这使得可以在高达最大残留限量的范围内对这些农药进行痕量分析。基于构建的校准曲线，估计苹果皮中福美双和carbaryl 的农药浓度分别为 2.5 µg/mL 和 0.012 µg/mL。此外，PET/ITO/Ag SERS 平台满足痕量农药分析所需的其他光谱特性，例如易于制备、成本效益高的方法，以及专门设计的物理特性，特别是灵活性和透明度，这拓宽了对不规则表面的采样通用性。
