Fluorescence anisotropy studies of molecularly imprinted polymers

Abstract

A molecularly imprinted polymer (MIP) is a biomimetic material that can be used as a biochemical sensing element. We studied the steady-state and time-resolved fluorescence and fluorescence anisotropy of anthracene-imprinted polyurethane. We compared MIPs with imprinted analytes present, MIPs with the imprinted analytes extracted, MIPs with rebound analytes, non-imprinted control polymers (non-MIPs) and non-MIPs bound with analytes to understand MIP's binding behaviour. MIPs and non-MIPs had similar steady-state fluorescence anisotropy in the range 0.11-0.24. Anthracene rebound in MIPs and non-MIPs had a fluorescence lifetime of tau = 0.64 ns and a rotational correlation time of phi(F) = 1.2-1.5 ns, both of which were shorter than that of MIPs with imprinted analytes present (tau = 2.03 ns and phi(F) = 2.7 ns). The steady-state anisotropy of polymer solutions increased exponentially with polymerization time and might be used to characterize the polymerization extent in situ.

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011

“…Traditionally, spectroscopic methods have been invaluable for the study of fundamental aspects of the molecular imprinting process, in particular, events taking place in prepolymerization mixtures. The work of recent years has seen a continued use of NMR, IR and UV‐Vis spectroscopies for characterizing monomer‐template interactions, to the point where such studies are becoming essential aspects of MIP design, either for the screening of monomers for interaction with template or for the validation of computational design data. A recent trend is the significant increase in the number of spectroscopic studies of ligand‐MIP interactions.…”

Recent advances in fluorescence anisotropy/polarization signal amplification

“…10,14 However, the main limitation of FPIA is that the detection of low mass compounds can be fairly restricted. 15–17 Over the last two decades, the investigation using nucleic acid aptamers as recognition units has broadened the applications of FA/FP assays 18,19 because of the great stability and high binding affinity of the aptamers and the advantages of aptamers over antibodies in ease of synthesis and labeling. 20 Different FA/FP assays have been established based on either direct or indirect aptamer recognition system.…”

Asymptotic solution of light transport problems in optically thick luminescent media

“…Hence, qualitatively, the loss of light flux (or photons) after n reabsorption events increases exponentially as QY n . The asymptotic assumption leading to the diffusion approximation is that this probability is close to unity (11). However, even when the quantum yield is quite large, say, 95%, if there is a significant overlap between the absorption and reemission spectra, the reabsorption effects can be significant.…”