title: A theoretical approach for designing fluorescent reagentless biosensors: The optical model.
abstract: In this paper a mathematical model describing the analytical signal obtained in fluorescence sensors is presented and compared with other commonly used models. The model starts from the Kubelka-Munk theory for solid surfaces but incorporates new theoretical improvements, being principally: (a) the increase in the effective optical pathlength due to the Scattering Induced Path Variation (SIPV), the incorporation of this parameter allows us to deduce that the fluorescence intensity from solid surfaces does not linearly change with the fluorophore concentrations; (b) the influence of the inner filter effect and how the error can be rectified and (c) the calculation of the scattering coefficients in sensor films for this kind of sensor. From this model it is possible to predict the effect of the fluorophore concentration, the sensor film scattering coefficient and the sample inner filter effect on the fluorescence signal. The conclusions obtained can be extended to other types of fluorescence measurements from solid surfaces.
authors.affiliation: ABG (Analytical Biosensors Group), INA (Instituto de Nanociencia de Aragón), Analytical Chemistry Department, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza, Spain. jgalban@unizar.es
authors.forename: Javier
authors.initials: J
authors.lastname: Galbán
authors.forename: Arantzazu
authors.initials: A
authors.lastname: Delgado-Camón
authors.forename: Vanesa
authors.initials: V
authors.lastname: Sanz
authors.forename: Isabel
authors.initials: I
authors.lastname: Sanz-Vicente
authors.forename: Susana
authors.initials: S
authors.lastname: de Marcos
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005453:Fluorescence; D008433:Mathematics; D008962:Models, Theoretical; D055095:Optics and Photonics; D012815:Signal Processing, Computer-Assisted; D013499:Surface Properties