Patent ID: 7026165
Filing Date: 2006-04-11
Classification: G01N,Y02A,Y10T

Abstract:
1. A method of operating absorbance-based chemical sensors to achieve calibration-free measurements, the method comprising the steps of: a) establishing wavelength accuracy to within about 2-3 nanometers; b) eliminating stray light at all wavelengths to about less than 0.1% incident light; c) preparing an analyte-selectlve reagent at a concentration; d) equilibrating the analyte-selective reagent to an analyte; e) taking an intensity reading of the equilibrated analyte-selective reagent and analyte at a first wavelength (I f) replacing the equilibrated analyte-selective reagent and analyte with a spectrophotometric blank solution; g) taking an intensity reading of the blank solution at the first wavelength (I h) calculating an absorbance ratio using the equation A i) calculating the sensor response with the molar absorptivities (ε) of the reacted (a) form of the analyto-selective reagent and the un-reacted form (b) of the analyte-selective reagent using the equation wherein when the analyte-selective reagent is prepared accurately and reproducibly at the concentration sensor readings between sensors are calibration-free.