Spatially scanned optical reader system and method for using same

Abstract

An optical reader system is described herein that uses a scanned optical beam to interrogate a biosensor to determine if a biomolecular binding event occurred on a surface of the biosensor. In one embodiment, the optical reader system includes a light source, a detector and a processor (e.g., computer, DSP). The light source outputs an optical beam which is scanned across a moving biosensor and while this is happening the detector collects the optical beam which is reflected from the biosensor. The computer processes the collected optical beam and records the resulting raw spectral or angle data which is a function of a position (and possibly time) on the biosensor. The processor can then analyze the raw data to create a spatial map of resonant wavelength (peak position) or resonant angle which indicates whether or not a biomolecular binding event occurred on the biosensor. Several other uses of the raw data are also described herein.

1 . A method for using an optical reader system, said method comprising the steps of: 
 generating a first optical beam which has a diameter that is smaller than a biosensor;    scanning the first optical beam across the biosensor;    collecting a second optical beam which is out-coupled from the biosensor;    processing the second optical beam to obtain raw spectral/angular data which is function of a position on the biosensor; and    recording the raw spectral/angular data.    
     
     
         2 . The method of  claim 1 , further comprising steps of repetitively scanning the first optical beam across the biosensor and collecting the second optical beam out-coupled from the biosensor to obtain raw spectral/angular data which is a function of time and position on the biosensor.  
     
     
         3 . The method of  claim 1 , wherein said scanning step and said collecting step are both performed while said biosensor is moved.  
     
     
         4 . The method of  claim 1 , wherein said scanning step and said collecting step are both performed while said biosensor is stationary.  
     
     
         5 . The method of  claim 1 , wherein said scanning step is performed by scanning the first optical beam on a predefined line across the biosensor.  
     
     
         6 . The method of  claim 1 , wherein said scanning step is performed by scanning the first optical beam across two-dimensions of the biosensor.  
     
     
         7 . The method of  claim 1 , wherein said scanning step is performed by scanning the first optical beam in an arbitrary manner across the biosensor.  
     
     
         8 . The method of  claim 1 , further comprising a step of using the recorded raw spectral/angular data to create a spatial map of one of the following: 
 resonant wavelength data;    resonant angle data;    reflected power;    reflectivity data;    peak width data;    local angle data; and    wavelength interrogation slope (WIS) data.    
     
     
         9 . The method of  claim 1 , further comprising a step of using the recorded raw spectral/raw data to create a spatial map of reflected power vs. reflected wavelength/angle which is then used to evaluate locations, quantities and sizes of defects on the biosensor.  
     
     
         10 . The method of  claim 1 , further comprising a step of using the recorded raw spectral/angular data to create a spatial map of reflected power that is used to locate an edge of a grating in the biosensor so that the biosensor could be properly re-located after being removed and reinserted into a path of the first and second optical beams.  
     
     
         11 . The method of  claim 1 , further comprising a step of analyzing the recorded raw spectral/angular data to ameliorate undesirable effects in measured wavelengths/angles that arise because of drifts within components on an optical path.  
     
     
         12 . The method of  claim 1 , wherein the biosensor has a reference region on which a target molecule cannot bind and a sample region on which the target molecule can bind, and wherein the raw spectral/angular data associated with the sample region is used to detect a biomolecular binding event and the raw spectral/angular data associated with the reference region is used to reference out spurious changes that can adversely affect the detection of the biomolecular binding event.  
     
     
         13 . The method of  claim 1 , further comprising a step of simultaneously interrogating a plurality of biosensors which are located in a plurality of wells in a microplate.  
     
     
         14 . The method of  claim 1 , wherein said biosensor has at least one predefined patterned reference region on which target molecules cannot bind and at least one predefined patterned sample region on which the target molecules can bind.  
     
     
         15 . The method of  claim 1 , wherein said scanning step is performed by using the first optical beam to interrogate spatially multiplexed targets on the biosensor which is located within a well of a microplate.  
     
     
         16 . The method of  claim 1 , wherein said scanning step is performed by using the first optical beam to interrogate spatially patterned sample/reference regions on the biosensor to reduce the undesired effects of spatial gradients on target immobilization, non-specific binding, sensor wavelength interrogation slope (WIS) variation, temperature and/or other environmental perturbations.  
     
     
         17 . The method of  claim 1 , wherein said scanning step is performed by using the first optical beam to interrogate spatially multiplexed targets.  
     
     
         18 . The method of  claim 1 , wherein said biosensor is a resonant waveguide grating biosensor.  
     
     
         19 . The method of  claim 1 , wherein said biosensor is a surface plasmon resonance biosensor.  
     
     
         20 . The method of  claim 1 , wherein said biosensor includes at least one fiducial marking thereon which is used to determine a position of the biosensor relative to the optical reader system.