Integrated optofluidic system using microspheres

Abstract

An integrated optofluidic system for trapping and transporting particles for analysis is provided comprising a planar substrate; a microfluidic channel; and a waveguide integrated with the channel. A microsphere particle in the integrated optofluidic system can act as a cavity, allowing light to circulate many thousands of times around the circumference of the microsphere. Optical trapping and transport is used for nanoscale positioning to excite the microsphere resonances. Sensitive measurements on molecules can be accomplished by monitoring changes in whispering gallery modes (WGMs) that propagate around the circumference of the microsphere. By using a broadband or supercontinuum light source, a microsphere can be trapped and many WGM resonances can be excited through the visible and near-infrared wavelengths simultaneously. After the resonances are measured using the waveguide transmission, the microsphere can be freed by decreasing the optical power and the process repeated with a different microsphere.

1 . An integrated optofluidic system for trapping and transporting individual particles for analysis comprising:
 a light source configured to produce light over a wavelength range;   a planar substrate;   a microfluidic channel;   a sensor region or detection region fluidically connected to the microfluidic channel; and   a waveguide integrated with the microfluidic channel through which the light is propagated, wherein the waveguide is configured to transport the individual particles to an interface that intersects the waveguide and retain the particles at the interface.   
     
     
         2 . (canceled) 
     
     
         3 . The integrated optofluidic system of  claim 1  wherein the particles are microspheres. 
     
     
         4 . The integrated optofluidic system of  claim 3  wherein the microspheres are functionalized. 
     
     
         5 . The integrated optofluidic system of  claim 4  wherein the functionalized microspheres comprise an identifier binding ligand that will bind a decoder binding ligand such that the identification of an analyte can be elucidated. 
     
     
         6 . The integrated optofluidic system of  claim 1  wherein the waveguide optically traps particles out of the microfluidic channel. 
     
     
         7 . The integrated optofluidic system of  claim 1  wherein the particles are trapped, stopped or retained within the sensor region or detection region. 
     
     
         8 . The integrated optofluidic system of  claim 7  wherein the trapped particles continue to move in the direction of the light propagated through the waveguide. 
     
     
         9 - 13 . (canceled) 
     
     
         14 . The integrated optofluidic system of  claim 1  comprising a sample inlet port wherein the microfluidic channel is fluidically connected to the sample inlet port. 
     
     
         15 . The integrated optofluidic system of  claim 1  comprising at least one sample handling well comprising a well inlet port and a well outlet port wherein:
 the well inlet port and the well outlet port are fluidically connected to the sample handling well to allow fluid contact between the sample inlet port and the sample handling well; and 
 the well outlet port is fluidically connected to the microfluidic channel. 
 
     
     
         16 . The integrated optofluidic system of  claim 15  wherein the well inlet port and the well outlet port are the same port. 
     
     
         17 . A method for trapping and transporting a particle for analysis comprising the steps of:
 providing a waveguide;   optically trapping the particle with the waveguide;   exciting a resonant light scattering signature of the particle with a light source that produces light over an analytical wavelength range; and   measuring the resonant light scattering signature of the particle using the waveguide transmission.   
     
     
         18 . The method of  claim 17  wherein the light source is a broadband light source and the analytical wavelength range is visible and near-infrared. 
     
     
         19 . The method of  claim 18  wherein the broadband light source produces visible and near-infrared wavelengths simultaneously. 
     
     
         20 . The method of  claim 17  wherein the light source is a supercontinuum light source. 
     
     
         21 . A method for trapping and transporting a particle for analysis comprising the steps of:
 providing an integrated optofluidic system, wherein the system comprises:
 a planar substrate; 
 a microfluidic channel; 
 a sensor region or detection region fluidically connected to the microfluidic channel; and 
 a waveguide integrated with the microfluidic channel through which light is propagated; 
   introducing the particle into the integrated optofluidic system;   optically trapping the particle in the sensor region or detector region with the waveguide;   exciting a resonant light scattering signature of the particle with a light source that produces light over an analytical wavelength range; and   measuring the resonant light scattering signature of the particle using the waveguide transmission.   
     
     
         22 . The method of  claim 21  further comprising, after the measuring step, the step of releasing the particle by decreasing optical power or changing the wavelength of the light. 
     
     
         23 . The method of  claim 21  wherein the light source is a broadband light source and the analytical wavelength range is visible and near-infrared. 
     
     
         24 . The method of  claim 23  wherein the broadband light source produces visible and near-infrared wavelengths simultaneously. 
     
     
         25 . (canceled) 
     
     
         26 . The method of  claim 21  wherein the resonant light scattering signature comprises whispering gallery mode (WGM) resonance. 
     
     
         27 . The method of  claim 21  wherein the steps of the method are repeated with a second particle. 
     
     
         28 - 31 . (canceled)