本文报道了一种利用聚偏二氟乙烯（Polyviny Lidene Fluoride,PVDF）微孔滤膜为载体的三聚氰胺(Melamine,MAM)的简便快速痕量分析技术。通过柠檬酸钠还原法制得平均粒径为30 nm的纳米金溶胶,加入不同浓度的三聚氰胺后金纳米粒子快速聚集,这种纳米金聚集体可以通过简便快捷的过滤技术截留在PVDF微孔滤膜表面,进而用于SERS检测,在水溶液中最低检测浓度为0.05 mg/L。我们进一步在牛奶样品中进行检测,在牛奶中检测限可以达到1 mg/L,满足大部分国家规定的婴儿配方食品中三聚氰胺的限量值为1 mg/kg的参考标准。该分析方法制备过程简单、成本低廉、总分析时间短,易于实现现场快速灵敏检测,应用前景广阔。

We demonstrate an extremely simple and practical surface-enhanced Raman spectroscopy (SERS) technique for trace melamine detection in milk with PVDF(Polyviny Lidene Fluoride) membranes as supports.Through trisodium citrate reduction method,gold nanoparticles with average diameter of 30 nm were obtained.Upon addition to trace-level melamine,gold nanoparticle solution exhibits a highly sensitive colour change from red to blue and rapid aggregation behavior within several minutes.The SERS detection platform was constructed after trapping the mixture of aggregates and melamine on PVDF membrane through a simple filter-based approach,and the lowest detectable concentration was 0.05 mg/L in aqueous solution.Moreover,for the melamine-spiked milk samples,the lowest detectable concentration was 1 mg/L,which could meet the requirement accepted by most countries that the threshold in infant formula was 1 ppm.Thus,due to the simple procedure,the low-cost of the substrates and the short total analysis time,our technique enables SERS to be practical for a broad range of analytical applications,including field-based detection of toxins in large volume samples.