High sensitivity broad-target porous graphene oxide capacitive vapor sensor

Abstract

The present invention discloses a novel capacitive vapor sensor comprising porous immobilized graphene oxide (pGO) on an electrode surface. Also disclosed is an in-situ process for the preparation of this sensor and various uses thereof.

1 . A capacitive vapor sensor comprising porous graphene oxide adsorbed on an electrode. 
     
     
         2 . The sensor of  claim 1  wherein said graphene oxide is a functionalized graphene oxide. 
     
     
         3 . The sensor of  claim 1 , whereas the electrode is an interdigitated electrode. 
     
     
         4 . An in-situ process for preparing the sensor of  claim 1 , said process comprising:
 i) Adsorbing graphene oxide on an electrode surface,   ii) Creating pores in said graphene oxide, to obtain porous graphene oxide adsorbed on said electrode surface.   
     
     
         5 . The process of  claim 4 , wherein said adsorbing of said graphene oxide on said electrode surface is achieved by contacting said electrode surface with a graphene oxide solution or a graphene oxide suspension. 
     
     
         6 . The process of  claim 5 , wherein said contacting is performed at a temperature ranging from 10° C. to 60° C. 
     
     
         7 . The process of  claim 5 , wherein said contacting is performed for an incubation time of at least 5 minutes. 
     
     
         8 . The process of  claim 7 , wherein said contacting is performed for an incubation time of at least 1 hour. 
     
     
         9 . The process of  claim 4 , wherein creating said pores in said graphene oxide is obtained by a process selected from hydrothermal, irradiation, polymerization, grafting, template based, annealing, electroplating deposition, oxidative coupling of primary amines, steam etching, expansion and freeze-drying. 
     
     
         10 . The process of  claim 4 , wherein said adsorbing of said graphene oxide on said electrode surface is achieved by contacting said electrode surface with a graphene oxide solution, followed by slow drying said graphene oxide solution at room temperature to obtain an assembly consisting of an electrode coated with a partially-dried graphene oxide,
 further wherein said creating of said pores in said graphene oxide is obtained by freeze-drying said assembly to obtain a porous graphene oxide film adsorbed on said electrode.   
     
     
         11 . The process of  claim 4 , wherein said adsorbing of said graphene oxide on said electrode surface is achieved by contacting said electrode surface with a graphene oxide-ammonium carbonate suspension, to obtain an assembly consisting of an electrode coated with said graphene oxide-ammonium carbonate suspension,
 further wherein said creating of said pores in said graphene oxide is obtained by heating said assembly to about 100° C. for several minutes to obtain a porous graphene oxide film adsorbed on said electrode.   
     
     
         12 . The process of  claim 4 , wherein said graphene oxide is a functionalized graphene oxide. 
     
     
         13 . A capacitive vapor sensor prepared according to the process of any of  claims 4 - 12 . 
     
     
         14 . A capacitive vapor sensor, constructed as an array of at least two array elements, each element comprising the sensor of  claim 1 , further whereas each array element comprises a different functionalized or non-functionalized porous graphene oxide molecule. 
     
     
         15 . The use of the sensor of  claim 1  for detecting the presence of one or more vapor analytes in a vapor sample. 
     
     
         16 . The use of the sensor of  claim 14  for detecting the presence of one or more vapor analytes in a vapor sample. 
     
     
         17 . The use of any of  claims 15 - 16 , wherein said vapor analytes are selected from water, ammonia, volatile organic compounds, polar and non-polar volatile molecules. 
     
     
         18 . A method for detecting the presence of one or more vapor analytes in a vapor sample, said method comprising passing a vapor sample through the capacitive vapor sensor of  claim 1 .