Analytical Division, Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India.
Analytical Division, Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India.
Biosens Bioelectron. 2014 Sep 15;59:81-8. doi: 10.1016/j.bios.2014.03.019. Epub 2014 Mar 20.
A rapid, selective, and sensitive double-template imprinted polymer nanofilm-modified pencil graphite electrode was fabricated for the simultaneous analysis of phosphorus-containing amino acid-type herbicides (glyphosate and glufosinate) in soil and human serum samples. Since both herbicides respond overlapped oxidation peaks and only glyphosate is prone to nitrosation, n-nitroso glyphosate and glufosinate were used as templates for obtaining the well-resolved quantitative differential pulse anodic stripping voltammetric peaks on the proposed sensor. Toward sensor fabrication, a nano-structured polymer film was first grown directly on the electrode via initial immobilization of gold nanoparticles at its surface. This was followed by linking of monomeric (N-methacryloyl-l-cysteine) molecules through S-Au bonds. Subsequently, these molecules were subjected to free radical polymerization, in the presence of templates, cross linker, initiator, and multiwalled carbon nanotubes as pre-polymer mixture. The modified sensor observed wide linear ranges (3.98-176.23 ng mL(-1) and 0.54-3.96 ng mL(-1)) of simultaneous analysis with detection limits as low as 0.35 and 0.19 ng mL(-1) (S/N=3) for glyphosate and glufosinate, respectively, in aqueous samples. The respective oxidation peak potentials of both analytes were found to be substantially apart by 265 mV. This enabled the simultaneous determination of one target in the presence of other, without any cross reactivity, interferences, and false-positives, in real samples.
一种快速、选择性和灵敏的双模板印迹聚合物纳米膜修饰的铅笔石墨电极被制备用于同时分析土壤和人血清样品中的含磷氨基酸型除草剂（草甘膦和草铵膦）。由于两种除草剂都有重叠的氧化峰响应，而只有草甘膦容易亚硝化，因此使用 n-亚硝基草甘膦和草铵膦作为模板，在提出的传感器上获得了良好分辨的定量差分脉冲阳极溶出伏安峰。为了制备传感器，首先通过在电极表面初始固定金纳米粒子，在电极上直接生长纳米结构聚合物薄膜。接着，通过 S-Au 键连接单体（N-丙烯酰基-L-半胱氨酸）分子。随后，在模板、交联剂、引发剂和多壁碳纳米管作为预聚物混合物的存在下，这些分子经历自由基聚合。修饰后的传感器在水溶液中对同时分析的线性范围很宽（草甘膦为 3.98-176.23ng/mL，草铵膦为 0.54-3.96ng/mL），检测限低至 0.35 和 0.19ng/mL（S/N=3）。两种分析物的相应氧化峰电位相差 265mV。这使得在存在其他物质的情况下，能够同时测定一个目标物，而没有任何交叉反应、干扰和假阳性，在实际样品中。
