Method for Modifying the Surfaces of Resonant Sensors

Abstract

Surface modifications to sensors in an array give the sensors different functionalities for adsorbing or binding molecules. A method for modifying surfaces of resonant sensors comprises depositing and patterning a first pre-coating material such that the first pre-coating material coats a first one of the resonant sensors and does not coat a second one of the resonant sensors. Both the first and second resonant sensors are then coated with a receptor material. The first resonant sensor that is coated with a combination of the first pre-coating material and the receptor material has a different ability to adsorb or bind a mass of at least one analyte than does the second resonant sensor that is coated with the receptor material without the first pre-coating material. In some examples, an array of sensors is fabricated with N sensors having up to N different pre-coating materials underlying a coating of the same receptor material.

What is claimed is: 
     
         1 . A method for modifying surfaces of resonant sensors, the method comprising:
 a) depositing and patterning a first coating material such that the first coating material coats a first one of the resonant sensors and does not coat a second one of the resonant sensors; and   b) coating both the first and second resonant sensors with a receptor material, wherein the first coating material and the receptor material are selected such that the first resonant sensor that is coated with a combination of the first coating material and the receptor material has a different ability to adsorb, absorb or bind a mass of at least one analyte than does the second resonant sensor that is coated with the receptor material without the first coating material.   
     
     
         2 . The method of  claim 1 , wherein the first coating material comprises gold, and the second resonant sensor, that is not coated with the first coating material, has a surface of native silicon or silicon oxide on which the receptor material is coated. 
     
     
         3 . The method of  claim 1 , wherein the step of coating both the first and second resonant sensors with the receptor material is preceded by the step of depositing and patterning a second coating material such that the second coating material coats the second sensor and does not coat the first sensor, wherein the second coating material is different than the first coating material, and the first and second coating materials and the receptor material are selected such that the second resonant sensor that is coated with the combination of the receptor material covering the second coating material has a different ability to adsorb, absorb or bind a mass of the analyte than does the first resonant sensor that is coated with a combination of the receptor material covering the first coating material. 
     
     
         4 . The method of  claim 3 , wherein the step of coating the first and second resonant sensors with the receptor material further comprises coating at least a third resonant sensor with the receptor material, wherein the third resonant sensor has a surface of native silicon or silicon oxide on which the receptor material is coated. 
     
     
         5 . The method of  claim 3 , wherein the first and second coating materials comprise metals. 
     
     
         6 . The method of  claim 3 , wherein the first coating material is gold and the second coating material comprises aluminum oxide. 
     
     
         7 . The method of  claim 1 , wherein the resonant sensors are coated with the receptor material by spin coating. 
     
     
         8 . The method of  claim 1 , wherein the receptor material comprises 3-Aminopropyltrimethoxysiloxane (AMO). 
     
     
         9 . The method of  claim 1 , wherein the receptor material comprises a mixture of 3-Aminopropyltrimethoxysiloxane (AMO) and Propyltrimethoxysiloxane (PTMS). 
     
     
         10 . The method of  claim 1 , wherein each of the resonant sensors comprises a capacitive micromachined ultrasound transducer (cMUT).