Experimental determination of the sensitivity of Bloch surface waves based sensors.
Detection of glucose in water solution for several different concentrations has been performed with the purpose to determine the sensitivity of Near Infrared Bloch Surface Waves (lambda = 1.55microm) upon refractive index variations of the outer medium. TE-polarized electromagnetic surface waves are excited by a prism on a silicon nitride multilayer, according to the Kretschmann configuration. The real-time reflectance changes induced by discrete variations in glucose concentration has been revealed and analyzed. Without using any particular averaging strategy during the measurements, we pushed the device detection limit down to a glucose concentration of 2.5mg/dL, corresponding to a minimum detectable refractive index variation of the water solution as low as 3.8.10(-6).
Giorgis
Fabrizio
F
Materials and Microsystems Laboratory - (lamda)Lab, Politecnico of Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy. fabrizio.giorgis@polito.it
Descrovi
Emiliano
E
Summonte
Caterina
C
Dominici
Lorenzo
L
Michelotti
Francesco
F
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D005947:Glucose / Q000032:analysis*; D011827:Radiation; D013499:Surface Properties
D005947:Glucose