Method for biomolecular sensing and system thereof

Abstract

A sensing system and method for biomolecular sensing. The system includes: a receptor for the at least one target, the receptor including a substrate and a transparent coating on the substrate having front and back surfaces; a light source positioned to direct at least a portion of light from the light source toward the coating on the receptor; and a detector positioned to capture the light reflected from the front and back surfaces of the coating, the detector identifying presence of at least one target based on a change in the interference pattern of captured light.

1 . A sensor system for sensing at least one target, the system comprising: 
 a receptor for the at least one target, the receptor comprising a substrate and a coating on the substrate having front and back surfaces, and one or more adsorbates attached to the front surface of the coating, said one or more adsorbates being capable of recognizing the at least one target;    a light source positioned to direct at least a portion of light from the light source toward the coating on the receptor in a manner effective to result in a condition of near perfect interference where the reflectance is less than 10 −4 ; and    a detector positioned to measure the light reflected from the front and back surfaces of the coating, the detector identifying presence of at least one target based on the measured reflected light.    
   
   
       2 . The system as set forth in  claim 1  further comprising at least one polarizer in a path of the at least a portion of light from the light source.  
   
   
       3 . The system as set forth in  claim 2  further comprising a rotator connected to the polarizer.  
   
   
       4 . The system as set forth in  claim 1  wherein the light source directs the at least a portion of the light toward the coating at a non-normal angle of incidence.  
   
   
       5 . The system as set forth in  claim 4  wherein the substrate is silicon and the coating is silicon dioxide.  
   
   
       6 . The system as set forth in  claim 5  wherein the receptor is present in a medium of air, the angle of incidence being about 70.5 degrees.  
   
   
       7 . The system as set forth in  claim 5  wherein the receptor is present in an aqueous environment, the angle of incidence being about 85.5 degrees, the system further comprising at least one prism in a path of the at least a portion of light.  
   
   
       8 . The system as set forth in  claim 4  wherein the substrate is silicon and the coating comprises an intermediate silicon nitride or titanium dioxide coating and an external silicon dioxide coating.  
   
   
       9 . The system as set forth in  claim 1  wherein the one or more adsorbates are selected from the group of non-polymeric small molecules, polypeptides or proteins, oligonucleotides, and combinations thereof.  
   
   
       10 . The system as set forth in  claim 1  wherein a thickness of the coating is based on at least one of an angle of incidence of the at least a portion of the light on the coating and a wavelength of the light to result in the condition of near perfect interference.  
   
   
       11 . The system as set forth in  claim 1  wherein the light from the light source is at least one of collimated, monochromatic, and polarized.  
   
   
       12 . The system as set forth in  claim 1  wherein the detector captures a single polarization of the reflected light.  
   
   
       13 . The system as set forth in  claim 1  wherein the detector is an imaging array that captures an image of at least a substantial portion of the surface of the receptor.  
   
   
       14 . A method for sensing at least one target, the method comprising: 
 providing a receptor for the at least one target, the receptor comprising a substrate and a coating on the substrate having front and back surfaces, and one or more adsorbates attached to the front surface of the coating, said one or more adsorbates being capable of recognizing the at least one target;    directing a light at the front and back surfaces of the coating on the receptor in a manner effective to result in a condition of near perfect interference where the reflectance is less than 10 −4 ;    measuring the light reflected from the front and back surfaces of the coating on the receptor; and    providing an output identifying the at least one target based on the measured reflected light.    
   
   
       15 . The method as set forth in  claim 14  further comprising polarizing the directed light in one direction.  
   
   
       16 . The method as set forth in  claim 15  further comprising rotating the polarizing of the light.  
   
   
       17 . The method as set forth in  claim 14  further comprising polarizing the reflected light in one direction.  
   
   
       18 . The method as set forth in  claim 17  further comprising rotating the polarizing of the light.  
   
   
       19 . The method as set forth in  claim 14  wherein the light source directs the at least a portion of the light toward the coating at a non-normal angle of incidence.  
   
   
       20 . The method as set forth in  claim 14  wherein the one or more adsorbates are selected from the group of non-polymeric small molecules, polypeptides or proteins, oligonucleotides, and combinations thereof.  
   
   
       21 . The method as set forth in  claim 14  wherein a thickness of the coating is based on at least one of an angle of incidence of the light on the coating and a wavelength of the light.  
   
   
       22 . The method as set forth in  claim 14  wherein the light is at least one of collimated, monochromatic, and polarized.  
   
   
       23 . The method as set forth in  claim 14  wherein the measuring the reflected light further comprises capturing an image of at least a substantial portion of the surface of the receptor.  
   
   
       24 . The method as set forth in  claim 14  wherein the substrate is silicon and the coating is silicon dioxide.  
   
   
       25 . The method as set forth in  claim 14  wherein the substrate is silicon and the coating comprises an intermediate silicon nitride or titanium dioxide coating and an external silicon dioxide coating.