W. Li et al., Quantitative analysis model for fiber-optic chemical sensors based on fluorescence quenching for analytes and its application, ACT CHIM S, 59(1), 2001, pp. 109-114
Because the fiber - optic chemical sensors based on the fluorescence quench
ing has an adjustable short distance from the membrane to the end of fiber
optics, forming a space of microcell, a diminution of fluorescence is induc
ed by inner filter effects, involving absorption of both excited light from
the light source and emitted light from the membrane. If the absorption sp
ectra of analytes overlap the fluorescence excitation and/or emission spect
ra of the fluoroprobe in the membrane, the quenching signal of the fiber -
optic chemical sensors would be produced by the resonance energy transfer.
In addition, dynamic quenching happens to some haloid, heavy metal compound
s and aromatic nitro organic compounds. According to the structural charact
erization of the filer - optic chemical sensors based on fluorescence quenc
hing and the mechanism of fluorescence multiple quenching, a non - linear m
athematical model was. deduced and described for the quantitative analysis
model for the fiber - optic chemical sensors. A multiple model regression t
echnique for the quantitative analysis model was reported to provide rapidl
y and directly the relations between the response signal and the concentrat
ion of analytes and establish linear regression equation for predicting the
concentration of analytes. The technique was applied to fit best mathemati
cal model from the control samples of the therapeutic drugs based on the re
sponse of fiber - optic chemical sensors, such as metronidazole, nitrofuran
toin and ofloxacin. The pyrenebutyric acid was chosen as a fluoroprobe for
constructing the filer - optic chemical sensor to response the samples. The
experimental results showed that these models had some good characteristic
s and gave an alternative method for establishing quantitative analysis mod
els for the filer - optic chemical sensors.