Transdermal systems, devices, and methods to optically analyze an analyte
The invention provides transdermal optical analysis systems, test sensors, methods, and kits for determining the presence and/or concentration of at least one analyte in a fluid sample. The system includes a transdermal test sensor including an aqueous material including at least one analyte selective reagent and at least one optically active moiety. The optical system preferably uses fluorescent spectroscopy to correlate fluorescent emission or adsorption from a dye with the analyte concentration of the sample. An optical light source and/or detector may be housed with the aqueous material in a housing or external to the housing of the aqueous material.
1. A non-invasive method for determining a concentration of at least one analyte in a fluid, the method comprising:
providing a transdermal test sensor including an aqueous material and a reagent system within the aqueous material, wherein the aqueous material is held between a top adhesive and a bottom adhesive within a volume defined by a semipermeable membrane and an additional membrane, the bottom adhesive adapted to adhere the test sensor to tissue, the test sensor further including an optical screen in contact with the additional membrane and the top adhesive and adapted to allow light communication with the aqueous material;
contacting porated tissue with the semipermeable membrane of the transdermal test sensor;
allowing sufficient time for the fluid sample to traverse to an external surface of the porated tissue and enter the aqueous material external to the porated tissue, the reagent system including at least one analyte selective reagent, at least one optically active moiety, and a reference dye;
applying at least one wavelength of light to the aqueous material;
detecting at least one wavelength of light from the aqueous material; and
correlating an alteration of the applied light to the detected light with the concentration of the at least one analyte in the fluid sample.
2. The method of claim 1 , wherein the at least one optically active moiety includes a pH sensitive dye.
3. The method of claim 1 , wherein the analyte selective reagent includes at least one receptor and one or more species that the analyte displaces from the at least one receptor.
4. The method of claim 1 , wherein the analyte selective reagent includes at least one analyte binding moiety that undergoes a conformation change when contacted by the analyte.
5. The method of claim 1 , wherein the analyte selective reagent includes at least one analyte binding moiety that undergoes a change in electron withdrawing ability when contacted by the at least one analyte.
6. The method of claim 1 , wherein the optically active moiety includes a donor fluorescent dye and an acceptor fluorescent dye.
7. The method of claim 6 , wherein the concentration of the at least one analyte is correlated with a decrease in acceptor dye fluorescence in the presence of the at least one analyte as compared to the acceptor dye fluorescence in the absence of the at least one analyte.
8. The method of claim 1 , wherein the optically active moiety includes a donor fluorescent dye and a quencher.
9. The method of claim 1 , wherein the at least one analyte is selected from the group consisting of glucose, cholesterol, glutamate, lactate, and combinations thereof.
10. The method of claim 1 , wherein the at least one analyte is glucose.
11. The method of claim 1 , wherein two or more analytes are detected.
12. The method of claim 1 , wherein the fluid sample is interstitial fluid.
13. The method of claim 1 , wherein the correlating of the alteration of the applied light to the detected light with the concentration of the at least one analyte in the fluid sample is repeated at pre-selected time intervals.
14. The method of claim 13 , the pre-selected time intervals are at least once every 20 minutes for at least 24 hours.