Sensor for Fluorene Based on the Incorporation of an Environmentally Sensitive Fluorophore Proximal to a Molecularly Imprinted Binding Site

Abstract

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.

Molecular imprinting ratiometric fluorescence sensor for highly selective and sensitive detection of phycocyanin

“…As known, the NBD-Cl, as an amine reactive reagent, is not fluorescent until it is covalently linked (Carlson et al, 2006). As seen from Fig.…”

Composite of CdTe quantum dots and molecularly imprinted polymer as a sensing material for cytochrome c

“…Furthermore, in contrast to the natural antibody, the substantial advantages of artificial counterparts are their mechanical and chemical robustness and their production by self-assembling processes without time-consuming and complex synthesis. Combining the high selectivity of molecular imprinting and the fluorescent properties of QDs could develop new method for target analyte recognition (Haupt et al, 1998;Carlson et al, 2006;Turkewitsch et al, 1998;Li et al, 2007Li et al, , 2010Tu et al, 2008). In such nanoparticles-based sensing systems, binding a target molecule is translated into a sensor signal and fluorescence intensity changes when a target 0956-5663/$ -see front matter © 2010 Elsevier B.V. All rights reserved.…”

Molecularly imprinted polymer anchored on the surface of denatured bovine serum albumin modified CdTe quantum dots as fluorescent artificial receptor for recognition of target protein

“…Therefore, if we combine the high selectivity of molecular imprinting technology and excellent fluorescent characteristics of QDs, a new affinity material, with specific recognition cavity and responding to the binding event with significant fluorescence intensity change, could be prepared. However, considerable interest has been focused on the development of small molecules imprinted polymer coated QDs, producing protein imprinted polymer based QDs was still a challenge (Haupt et al, 1998;Carlson et Li et al, 2010;Lin et al, 2004Lin et al, , 2009Liu et al, 2010;Diltemiz et al, 2008;Wang et al, 2009;Zhang et al, 2011).…”