System and method for detecting presence of analytes using gratings

Abstract

The present invention is directed to an optical grating sensor configured to detect a phase change in light passing though the system due to a binding event caused by an analyte. The grating sensor may include a light source that may be, for example, a coherent light source. The invention may also include a first diffraction grating having a first period. A micro-electrical mechanical system (MEMS) may be displaced from the first diffraction grating and may be configured to modulate the light received form the coherent light source. An analyte recognition material may be disposed on the surface of the first grating. A detector may be configured to receive light form the coherent light source after the light has been diffracted from the first diffraction grating and modulated by the MEMS. In another embodiment of the present invention, the grating sensor may be configured to operate in two modes. The first mode may be a mode the detect a phase change in the light due to a binding event. The second mode may include the detection of fluorescence due to a binding event and may employ tagging of the analytes.

1 - 15 . (canceled) 
   
   
       16 . An apparatus, comprising:
 a grating-based optical sensor configured to operate in a first mode and a second mode, the first mode being configured to detect the presence of an analyte based on a binding event based on a phase change of light associated with a binding event, and the second mode being configured to detect the presence of the analyte using a label.   
   
   
       17 . The apparatus of  claim 16 , wherein the first mode employs the use of a micro-electrical mechanical system (MEMS) to modulate light received from a first grating, the first grating including an analyte recognition material. 
   
   
       18 . The apparatus of  claim 16 , wherein the grating-based optical sensor is configured to operate in the first mode and the second mode concurrently. 
   
   
       19 . The apparatus of  claim 16 , wherein the grating-based optical sensor is configured to operate selectively in the first mode and the second mode. 
   
   
       20 . The apparatus of  claim 16 , wherein the phase change of light is associated with a change in the grating optical height due to the binding event. 
   
   
       21 . The apparatus of  claim 16 , wherein the label is a fluorescent label and is attached to a conjugating substance to the analyte. 
   
   
       22 . The apparatus of  claim 16 , wherein the label is one of a luminescent label, a phosphorescent label, an up-converting label, a down-converting label, a bead-based label, or a metal-colloid label. 
   
   
       23 . A grating module, comprising:
 a first periodic diffractive grating;   a second periodic diffractive grating;   an analyte recognition material disposed on the first periodic diffractive grating and/or the second periodic diffractive grating; and   a detector adapted and configured to detect a change in phase of light diffracted and/or scattered by the first periodic diffractive grating and/or the second periodic diffractive grating.   
   
   
       24 . The grating module of  claim 23 , further comprising a positioning system adapted and configured to modulate an output signal of the grating module generated in response to incident light diffracted and/or scattered by the first periodic diffractive grating and/or the second periodic diffractive grating. 
   
   
       25 . The grating module of  claim 24 , wherein the positioning system is adapted and configured to move the first periodic diffractive grating relative to the second periodic diffractive grating. 
   
   
       26 . The grating module of  claim 25 , wherein the positioning system is adapted and configured to move only one of the first periodic diffractive grating and the second periodic diffractive grating. 
   
   
       27 . The grating module of  claim 23 , further comprising a coherent light source adapted and configured to source light incident upon the first periodic diffractive grating and/or the second periodic diffractive grating. 
   
   
       28 . The grating module of  claim 23 , wherein the analyte recognition material is disposed on both the first periodic diffractive grating and the second periodic diffractive grating. 
   
   
       29 . The grating module of  claim 23 , wherein the first periodic diffractive grating and/or the second periodic diffractive grating includes a modified surface adapted and configured to immobilize the analyte recognition material by chemical bonding and/or absorption. 
   
   
       30 . The grating module of  claim 23 , wherein the analyte recognition material is removably disposed on the first periodic diffractive grating and/or the second periodic diffractive grating. 
   
   
       31 . The grating module of  claim 23 , wherein an array of analyte recognition material(s) is disposed on the first periodic diffractive grating and/or the second periodic diffractive grating. 
   
   
       32 . The grating module of  claim 31 , wherein the first periodic diffractive grating and/or the second periodic diffractive grating comprise a modified surface adapted and configured to immobilize the array of analyte recognition material(s) at discrete locations on the modified surface. 
   
   
       33 . The grating module of  claim 31 , wherein the array of analyte recognition material(s) comprises multiple types of analyte recognition material. 
   
   
       34 . The grating module of  claim 23 , further comprising:
 a blocking material disposed on the first periodic diffractive grating and/or the second periodic diffractive grating,   wherein the blocking material is adapted and configured to reduce nonspecific binding of analytes and/or analyte recognition materials.   
   
   
       35 . An analyte detecting system including the grating module of  claim 23 . 
   
   
       36 . A grating module, comprising:
 means for diffracting and/or scattering light;   means, disposed on the means for diffracting and/or scattering, for bonding with an analyte; and   means for detecting a change in phase of light diffracted and/or scattered by the means for diffracting and/or scattering light.