原位生长法制备可擦拭柔性SERS基底应用于农药快速检测

Fabrication of Plasmonic Absorbent Cotton as SERS Substrate for Adsorption and Detection of Harmful Ingredients in Food

以医用脱脂棉为柔性载体,通过化学沉积法在脱脂棉表面沉积银纳米种子,进一步通过种子调制原位合成法制备脱脂棉-银等离子复合物柔性SERS基底。采用紫外-可见光吸收光谱、X射线衍射、红外光谱、透射电子显微镜、扫描电子显微镜及EDS元素分析对医用脱脂棉等离子体复合材料进行了表征。粒径约为70 nm的银纳米粒子紧密排列在脱脂棉纤维表面。脱脂棉-银柔性基底相较于刚性玻璃基底由于脱脂棉的吸附能力,其SERS活性可以提高6倍。进一步应用于苹果表面的福美双及鱼中孔雀石绿等农药残留物的检测,其检出限达到0.1 ppm。

In this study,we have demonstrated the deposition of Ag NPs by seed-mediated in situ growth method from electroless deposited Ag seeds on absorbent cotton.During the process of seed growth,the Ag seeds were electroless-deposited on the surface of absorbent cotton by reduction of Ag+by Sn2+,and the secondary growth step was carefully controlled by using a gentle reducing agent.The SnCl2 also provide sufficient adhesion to anchor the Ag NPs to the surface of absorbent cotton.Furthermore,the high absorbency feature of the flexible absorbent cotton could bring analyte enrichment effect during SERS measurement.The obtained flexible SERS substrate base on absorbent cotton-Ag was highly SERS active and shown 6 times higher enhancement in SERS signal of R6 G compared to the hard glass-Ag SERS substrate.The Ag NPS decorated absorbent cotton were employed as SERS substrate for detecting of hazardous residue from real food sample with irregular surface.