Method of filling an amperometric cell

A method for monitoring an analyte in a liquid sample comprising the steps of:

• a) drawing the sample into an amperometric electrochemical cell comprising a first insulating substrate carrying a first electrode, a second insulating substrate carrying a second electrode, said electrodes being disposed to face each other and spaced apart by less than 500 μm, and defining a sample reservoir therebetween, wherein at least one of said insulating substrates and the electrode carried thereon includes an electromagnetic radiation transmissive portion in registration with said reservoir;
• b) exposing the transmissive portion to electromagnetic radiation;
• c) monitoring a property of the electromagnetic radiation passing and/or reflected through said transmissive portion;
• d) comparing said monitored property with a value indicative of the cell being filled;
• and
• e) prior to, simultaneously with or after any one of steps b) to d) applying a potential across the electrochemical cell and measuring the resultant current to detect the analyte.

A method of determining whether an amperometric cell is filled with a liquid sample, said cell comprising a first insulating substrate carrying a first electrode, a second insulating substrate carrying a second electrode, said electrodes being disposed to face each other and spaced apart by less than 500 μm, and defining a sample reservoir therebetween, wherein at least one of said insulating substrates and the electrode carried thereon includes an electromagnetic radiation transmissive portion in registration with said reservoir, said method comprising the steps of:

• a) exposing said transmissive portion to electromagnetic radiation;
• b) monitoring a property of the electromagnetic radiation passing and/or reflected through said transmissive portion;
• and
• c) comparing said monitored property with a value indicative of the cell being filled.