目前，探索土壤，地下水，食品中的农药残留的新检测手段，正在受到广泛的兴趣与关注，但是要实现集灵敏度，选择性与低成本的简单易行的检测方法是相当困难的。
智能所仿生纳米传感器实验室王进副研究员与其合作者孔令涛博士后等人，利用一维金纳米颗粒独特的光学特性，合成了不同长宽比的一维金纳米颗粒，进行了无碳链的环糊精修饰，在最接近金表面的区域富集农残分子，依据拉曼特征指纹峰，对农残分子进行识别探测。该项成果运用了表面增强拉曼技术，借助于纳米尺寸的贵金属表面特殊的拉曼增强效应，选取了特定长宽比的一维纳米金颗粒，形象地作为光棒起到了对进出光子的放大作用，以起到增强待测农残分子的拉曼振动信号。进一步通过金棒表面环糊精的修饰对农残分子进行富集选择，可以形象地比喻为锁匙效应，即某些待测农残分子被有效地捕捉进入环糊精的口袋中，借此克服了农药残留检测中灵敏性与选择性的难题。
在上述工作基础上，智能所的研究组还将进一步合成设计不同杯腔的有机物对具有特殊光学特性的贵金属纳米颗粒进行修饰、组装，以实现对农药残留的超敏感检测。
原文出处：
J.Mater.Chem., DOI: 10.1039/c0jm00040j
Synthesis of novel decorated one-dimensional gold nanoparticle and its application in ultrasensitive detection of insecticide
Jin Wang, LingTao Kong, Zheng Guo, JingYao Xu and JinHuai Liu
Contamination of soil, groundwater and food with methyl parathion, which is one of the most hazardous insecticides, is causing wide concern. Motivated by the urgent demand for trace analysis of insecticide from environmental samples, searching for a novel highly sensitive or selective analytical approach has been a longstanding interest. The as-prepared one dimensional gold nanoparticles, with different aspect ratios, have been decorated with mono-6-thio--cyclodextrin so as to efficiently capture and detect methyl parathion insecticide via a surface enhanced Raman scattering (SERS) technique for the first time. A detailed comparison among different aspect ratios of the one dimensional gold nanoparticles suggests that the one dimensional gold nanoparticles with aspect ratio 2 can be provided as an excellent SERS active substrate for detecting the insecticide in the present study. Due to the efficient formation of a host–guest complex between the hybridized cavity and methyl parathion, identification of the insecticide can be observed at picomolar level according to the fingerprint Raman peaks. Excellent sensitivity and selectivity for detection of the insecticide using the hybridized one dimensional gold nanoparticles without a Raman label indicate that it is a simple and ultrasensitive approach for detecting insecticides in contrast with some other traditional detection approaches.
