Method of controlling degradation of trace gas sensors

Abstract

A method of avoiding or delaying degradation of a transduction molecule in a trace gas sensor by controlling oxygen exposure is disclosed. Degradation of the gas sensor can be avoided by storage of the sensor in a low-oxygen or substantially oxygen-free environment.

1 . A method of preserving a sensor, comprising: 
 a. providing a sensor comprising a transduction molecule, wherein said transduction molecule is used to detect the concentration of a trace gas; and    b. controlling the degradative effects of oxygen on said transduction molecule.    
   
   
       2 . The method according to  claim 1 , wherein said transduction molecule is within a sensing element with a surface area greater than 300 m2/g.  
   
   
       3 . The method according to  claim 2 , wherein said sensing element has a surface area greater than 390 m2/g.  
   
   
       4 . The method according to  claim 1 , wherein said sensor additionally comprises a matrix, and wherein said transduction molecule is embedded into said matrix.  
   
   
       5 . The method according to  claim 4 , wherein said transduction molecule is cytochrome-c and said matrix is a xerogel.  
   
   
       6 . A method of preserving a gas sensor, comprising: 
 a. providing a sensor housing comprising a sensor with a transduction molecule, wherein said transduction molecule is used to detect the concentration of a trace gas; and    b. purging oxygen from said sensor housing.    
   
   
       7 . The method according to  claim 6 , additionally comprising: 
 a. providing packaging;    b. purging oxygen from said packaging;    c. placing said sensor housing into said packaging, either before or after purging oxygen from said packaging; and    d. sealing said packaging.    
   
   
       8 . The method according to  claim 6 , wherein purging oxygen from said sensor housing is accomplished with nitrogen.  
   
   
       9 . The method according to  claim 7 , wherein purging oxygen from said packaging is accomplished with nitrogen.  
   
   
       10 . The method according to  claim 6 , wherein said sensor additionally comprises a matrix, and wherein said transduction molecule is embedded into said matrix.  
   
   
       11 . The method according to  claim 10 , wherein said transduction molecule is cytochrome-c and said matrix is a xerogel.  
   
   
       12 . A method of preserving a gas sensor, comprising: 
 a. providing a sealed permeable sensor housing comprising a sensor with a transduction molecule, wherein said transduction molecule is used to detect the concentration of a trace gas; and    b. using an oxygen absorber to remove oxygen from said sealed permeable sensor housing.    
   
   
       13 . The method according to  claim 12 , additionally comprising purging oxygen from said sensor housing before said sensor housing is sealed.  
   
   
       14 . The method according to  claim 12 , wherein oxygen is not purged from said sensor housing before said sensor housing is sealed.  
   
   
       15 . The method according to  claim 12 , wherein said sensor additionally comprises a matrix, and wherein said transduction molecule is embedded into said matrix.  
   
   
       16 . The method according to  claim 15 , wherein said transduction molecule is cytochrome-c and said matrix is a xerogel.  
   
   
       17 . A method of preserving a gas sensor, comprising: 
 a. providing a unsealed sensor housing comprising a sensor with a transduction molecule, wherein said transduction molecule is used to detect the concentration of a trace gas; and    b. using an oxygen absorber to remove oxygen from said unsealed permeable sensor housing.    
   
   
       18 . The method according to  claim 17 , additionally comprising purging oxygen from said sensor housing.  
   
   
       19 . The method according to  claim 17 , wherein oxygen is not purged from said sensor housing.  
   
   
       20 . The method according to  claim 17 , wherein said sensor additionally comprises a matrix, and wherein said transduction molecule is embedded into said matrix.  
   
   
       21 . The method according to  claim 20 , wherein said transduction molecule is cytochrome-c and said matrix is a xerogel.  
   
   
       22 . A sensor package, comprising: 
 a. a sensor housing, said sensor housing substantially free of oxygen;    b. a transduction molecule in said sensor housing, wherein said transduction molecule is used to detect the concentration of a trace gas; and    c. a package enclosing said sensor housing, wherein said package defines an environment around said sensor, and wherein said environment is substantially free of oxygen.    
   
   
       23 . The package according to  claim 22 , additionally comprising a matrix, wherein said transduction molecule is embedded into said matrix.  
   
   
       24 . The package according to  claim 23 , wherein said transduction molecule is cytochrome-c and said matrix is a xerogel.  
   
   
       25 . The package according to  claim 22 , additionally comprising an oxygen absorber in said package.  
   
   
       26 . The package according to  claim 22 , wherein said transduction molecule is in a sensing element, and said sensing element has a surface area greater than 300 m2/g.  
   
   
       27 . The package according to  claim 26 , wherein said sensing element has a surface area greater than 390 m2/g.