@article{chen04b,
  author = {Yin-Chu Chen and J. J. Brazier and M. Yan and Scott A. Prahl},
  title = {Fluorescence-Based Optical Sensor Design for Molecularly Imprinted Polymers},
  journal = {Sensors and Actuators B: Chemical},
  volume = {102},
  pages = {107--116},
  year = {2004},
  abstract = {Many studies have attempted to integrate an optical fibers or waveguides with molecularly imprinted polymer (MIP) as the sensing element; however, little work has been done on the fluorescence analysis of such sensing system. Two major factors affect the sensitivity of the fluorescence sensing system: 1) fluorescence collecting efficiency of the optical sensing system and 2) the strength of the analyte fluorescence signals. In this research, first, anthracene imprinted polyurethane films were fabricated and tested with their rebinding. Our imprinted polymers showed the rebinding to the imprinted polymers was six times more than to the non-imprinted polymers, which agreed with many of the published studies. Second, the optical properties of MIP were characterized quantitatively to provide the background knowledge to the theoretical analysis. It is shown that the background absorption coefficients increased while the solvent inside the polymer was evaporated. The absorption coefficient was determined to be $15\pm1\,cm^{-1}$ at the excitation (358\,nm) wavelength of anthracene and $3.5\pm0.8\,cm^{-1}$ at emission (404\,nm) wavelength in day one. \vskip2mm Finally, a theoretical model for the fluorescence output efficiency of a fluorescence-based molecularly imprinted polymer sensing system was reported and verified experimentally. \vskip2mm The theoretical model showed that the fluorescence signal increases with thickness and saturates at some point. Higher concentration of fluorophores tends to saturate earlier. The model also shows how the background absorption coefficients affect the output efficiency. This analysis provides an optimization strategy for sensor design. If the fluorescence output efficiency needs to be greater than 0.005\% to be detectable by the fluorometer, and if the system wants to detect at least 1\,ppm anthracene (or say $\mu_a^f = 0.063$\,cm$^{-1}$) with 0.1\,mm thick polymer sensing layer, the background absorption of the polymer needs to be smaller than 0.2\,cm$^{-1}$ if assuming the quantum yield of the analyte = 1 and assuming the polymer doesn't fluorese the same wavelength as the analyte.},
}