Reference electrode having a microfluidic flowing liquid junction

A method of manufacturing a flowing junction reference electrode, the method comprising:

• providing a chamber for receiving a reference electrolyte solution, wherein the chamber is configured to allow pressurization of the electrolyte solution;
• and
• providing a liquid junction member made of a polymer and having N discrete nanochannels, the nanochannels having diameters D and lengths L, wherein N is less than approximately 100,000, and wherein the member is in fluid communication with the electrolyte solution;
• filling said chamber with said reference electrolyte solution, said reference electrolyte solution having a viscosity η;
• pressurizing the electrolyte solution to a pressure PE;
• configuring the reference electrode such that the liquid junction member can be brought into fluid communication with a sample solution such that the junction member is situated between the electrolyte solution and the sample solution;
• and
• selecting ΔP, D, η, and L such that
• D
• 2
• ⁢
• Δ
• ⁢
• ⁢
• P
• 32
• ⁢
• η
• ⁢
• ⁢
• L
• is greater than about 0.1 centimeter per second, wherein ΔP is a pressure differential between PE and a pressure PS of the sample solution, and wherein ΔP is greater than approximately 10 psi and less than approximately 100 psi.

A method of manufacturing a flowing junction reference electrode, the method comprising:

• providing a chamber for receiving a reference electrolyte solution, wherein the chamber is configured to allow pressurization of the electrolyte solution;
• and
• providing a liquid junction member made of silicon, glass, or ceramic, and having N discrete nanochannels, the nanochannels having diameters D and lengths L, wherein N is less than approximately 100,000, and wherein the member is in fluid communication with the electrolyte solution;
• filling said chamber with said reference electrolyte solution, said reference electrolyte solution having a viscosity η;
• pressurizing the electrolyte solution to a pressure PE;
• configuring the reference electrode such that the liquid junction member can be brought into fluid communication with a sample solution such that the junction member is situated between the electrolyte solution and the sample solution;
• and
• selecting ΔP, D, η, and L such that
• D
• 2
• ⁢
• Δ
• ⁢
• ⁢
• P
• 32
• ⁢
• η
• ⁢
• ⁢
• L
• is greater than about 0.1 centimeter per second, wherein ΔP is a pressure differential between PE and a pressure PS of the sample solution, and wherein ΔP is greater than approximately 10 psi and less than approximately 100 psi.

A method of manufacturing a flowing junction reference electrode, the method comprising:

• providing a chamber for receiving a reference electrolyte solution, wherein the chamber is configured to allow pressurization of the electrolyte solution;
• and
• providing a liquid junction member having N discrete nanochannels, the nanochannels having diameters D and lengths L, wherein N is less than approximately 100,000, and wherein the member is in fluid communication with the electrolyte solution;
• filling said chamber with said reference electrolyte solution, said reference electrolyte solution having a viscosity η;
• providing means for pressurizing the electrolyte solution;
• pressurizing the electrolyte solution to a pressure PE;
• configuring the reference electrode such that the liquid junction member can be brought into fluid communication with a sample solution such that the junction member is situated between the electrolyte solution and the sample solution;
• and
• selecting ΔP, D, η, and L such that
• D
• 2
• ⁢
• Δ
• ⁢
• ⁢
• P
• 32
• ⁢
• η
• ⁢
• ⁢
• L
• is greater than about 0.1 centimeter per second, wherein ΔP is a pressure differential between PE and a pressure PS of the sample solution, and wherein ΔP is greater than approximately 10 psi and less than approximately 100 psi.

A method of manufacturing a flowing junction reference electrode, the method comprising:

• providing a chamber for receiving a reference electrolyte solution, wherein the chamber is configured to allow pressurization of the electrolyte solution;
• and
• providing a liquid junction member having N discrete nanochannels, the nanochannels having diameters D and lengths L, wherein N is less than approximately 100,000, and wherein the member is in fluid communication with the electrolyte solution;
• filling said chamber with said reference electrolyte solution, said reference electrolyte solution having a viscosity η;
• pressurizing the electrolyte solution to a pressure PE;
• configuring the reference electrode such that the liquid junction member can be brought into fluid communication with a sample solution such that the junction member is situated between the electrolyte solution and the sample solution;
• selecting ΔP, D, η, and L such that
• D
• 2
• ⁢
• Δ
• ⁢
• ⁢
• P
• 32
• ⁢
• η
• ⁢
• ⁢
• L
• is greater than about 0.1 centimeter per second, wherein ΔP is a pressure differential between PE and a pressure PS of the sample solution, and wherein ΔP is greater than approximately 10 psi and less than approximately 100 psi;
• and
• providing a sensing electrode.