Carlson Catherine A, Lloyd Julie A, Dean Stacey L, Walker Natalie R, Edmiston Paul L
Department of Chemistry, College of Wooster, Wooster, Ohio 44691, USA.
Anal Chem. 2006 Jun 1;78(11):3537-42. doi: 10.1021/ac051375b.
A fluorescence-based chemical sensor for fluorene was created by molecularly imprinting a sol-gel comprising the bridged silsesquioxane, bis(trimethoxysilylethyl)benzene. The template was covalently bound to the sol-gel matrix using a fluorene analogue functionalized silane. After chemical removal of template via cleavage of a carbamate linkage, an amine group was left that provided an attachment site for the environmentally sensitive fluorescent probe 7-nitrobenz-2-oxa-1,3-diazole (NBD). Fluorene binding was detected by a change in NBD fluorescence intensity induced by a difference in the local polarity around the probe when the recognition site is filled. Such an approach eliminated response to nonspecific binding to the matrix. Sensing films deposited on glass slides were shown to have response times of <60 s and detection limits below 10 parts-per-trillion. Binding experiments demonstrated that the materials had good selectivity for fluorene over close structural analogues including naphthalene, fluoranthene, and anthracene. However, the sensing design is limited by a lack of reversibility following fluorene binding.
通过分子印迹包含桥联倍半硅氧烷双（三甲氧基硅基乙基）苯的溶胶 - 凝胶，制备了一种基于荧光的芴化学传感器。使用芴类似物功能化硅烷将模板共价结合到溶胶 - 凝胶基质上。通过氨基甲酸酯键的裂解化学去除模板后，留下一个胺基，该胺基为环境敏感荧光探针7 - 硝基苯并 - 2 - 恶唑 - 1,3 - 二唑（NBD）提供了附着位点。当识别位点被占据时，通过探针周围局部极性差异引起的NBD荧光强度变化来检测芴的结合。这种方法消除了对与基质非特异性结合的响应。沉积在载玻片上的传感膜显示出响应时间小于60秒，检测限低于万亿分之十。结合实验表明，该材料对芴具有良好的选择性，优于包括萘、荧蒽和蒽在内的结构类似物。然而，传感设计受到芴结合后缺乏可逆性的限制。
