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Fiber optic based sensor technologies have many significant advantages over electrochemical sensors, and as a result
have broad application for sensing in biology, agriculture and medicine. An important component of fiber optic
biosensor is the sensing element. Usually, a polymer matrix containing the analyte specific fluorescent dye is
immobilized on one end of the fiber optic probe. The polymer matrix provides mechanical stability to the immobilized
membrane and entraps the fluorescent dye molecules. The target analyte diffuses into the membrane polymer and
quenches the fluorescent dye. This optical interaction between the analyte and fluorescent dye dynamically changes the
fluorescence lifetime of the dye. These changing fluorescent lifetimes reveal information about the target analyte
concentration. Although the fluorescent lifetime of the dye is of primary interest, high signal-to-noise ratio (SNR) is also
very desirable. Conventionally, complex electronics is implemented to achieve high SNR. Various signal processing
methods such as signal amplification and filtering are implemented to achieve high SNR. In this study, we report optical
signal amplification by modification of the dye-polymer matrix by addition of titanium oxide particles. The addition of
titanium oxide particles enhanced the optical signal intensity. Optical performances of different sizes and concentrations
of titanium oxide particles are compared. We believe that this increased optical intensity is due to increased optical
scattering in the dye-polymer matrix. We also compare the performance of titanium oxide particles to gold and other
material particles to experimentally probe the exact nature of light scattering in the dye-polymer matrix.
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