Mass biosensor method with quantified sensor renewal

Abstract

A mass biosensor method provides enhanced quantification of analyte concentrations in a sample. In a direct approach, an analyte is derivatized to form an analyte chelate and then specifically bound to a sensor. In an indirect approach, a complement of the analyte is derivatized to form a complement chelate which is then bound to a sensor. In a direct/indirect hybrid approach, an analog of the analyte is derivatized to form an analog chelate that is bound to a sensor in competition with the sample analyte. In all three approaches, mass measurements taken as the ligand chelate attaches to the sensor permit the concentration of the analyte in the sample to be calculated. Once measurement is completed, a dissociation treatment is applied to dissociate the derivatized species from the sensor so that the sensor can be reused. The effects of the dissociation treatment can be monitored using phosphorescence detection. The results obtained during monitoring can be compared with a predetermined threshold to ensure complete dissociation while avoiding alteration of the sensor surface. This procedure permits precision renewal of a sensor to maximize the number of times a sensor can be used. Moreover, this method allows quantification to be performed using the same sensor and coating in place during calibration, minimizing systematic errors and enhancing quantification accuracy.