School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, 510275, China.
Anal Chem. 2011 Oct 1;83(19):7531-41. doi: 10.1021/ac201864f. Epub 2011 Sep 7.
A new fabrication strategy of the graphene-coated solid-phase microextraction (SPME) fiber is developed. Graphite oxide was first used as starting coating material that covalently bonded to the fused-silica substrate using 3-aminopropyltriethoxysilane (APTES) as cross-linking agent and subsequently deoxidized by hydrazine to give the graphene coating in situ. The chemical bonding between graphene and the silica fiber improve its chemical stability, and the obtained fiber was stable enough for more than 150 replicate extraction cycles. The graphene coating was wrinkled and folded, like the morphology of the rough tree bark. Its performance is tested by headspace (HS) SPME of polycyclic aromatic hydrocarbons (PAHs) followed by GC/MS analysis. The results showed that the graphene-coated fiber exhibited higher enrichment factors (EFs) from 2-fold for naphthalene to 17-fold for B(b)FL as compared to the commercial polydimethylsioxane (PDMS) fiber, and the EFs increased with the number of condensed rings of PAHs. The strong adsorption affinity was believed to be mostly due to the dominant role of π-π stacking interaction and hydrophobic effect, according to the results of selectivity study for a variety of organic compounds including PAHs, the aromatic compounds with different substituent groups, and some aliphatic hydrocarbons. For PAHs analysis, the graphene-coated fiber showed good precision (<11%), low detection limits (1.52-2.72 ng/L), and wide linearity (5-500 ng/L) under the optimized conditions. The repeatability of fiber-to-fiber was 4.0-10.8%. The method was applied to simultaneous analysis of eight PAHs with satisfactory recoveries, which were 84-102% for water samples and 72-95% for soil samples, respectively.
一种新型的石墨烯涂层固相微萃取（SPME）纤维的制备策略被开发出来。首先使用氧化石墨作为起始涂层材料，该氧化石墨通过 3-氨丙基三乙氧基硅烷（APTES）作为交联剂与熔融硅基底共价结合，随后通过联氨还原得到原位石墨烯涂层。石墨烯与二氧化硅纤维之间的化学键合提高了其化学稳定性，并且得到的纤维在超过 150 次重复萃取循环中仍然稳定。石墨烯涂层呈褶皱和折叠状，类似于粗糙树皮的形态。通过顶空（HS）SPME 对多环芳烃（PAHs）进行测试，并通过 GC/MS 分析来检验其性能。结果表明，与商业聚二甲基硅氧烷（PDMS）纤维相比，石墨烯涂层纤维对萘的富集因子（EF）提高了 2 倍，对 B(b)FL 的 EF 提高了 17 倍，而对 PAHs 的 EF 则随着稠环数的增加而增加。根据对包括 PAHs、不同取代基的芳香族化合物和一些脂肪族烃在内的多种有机化合物的选择性研究结果，这种强吸附亲和力主要归因于π-π堆积相互作用和疏水效应的主导作用。对于 PAHs 的分析，在优化条件下，石墨烯涂层纤维显示出良好的精密度（<11%）、低检测限（1.52-2.72ng/L）和较宽的线性范围（5-500ng/L）。纤维之间的重复性为 4.0-10.8%。该方法应用于同时分析 8 种 PAHs，水样的回收率为 84-102%，土壤样品的回收率为 72-95%。
