System and methods for blood glucose sensing

A test strip for testing a blood sample, said test strip comprising:

• a first substrate;
• a second substrate, said second substrate defining a sample chamber for said blood sample;
• at least four electrodes, disposed on said first substrate, for measuring at least one electrical characteristic of said blood sample in said sample chamber, said at least four electrodes including a working electrode, a counter electrode, a fill-detect anode, and a fill-detect cathode;
• a plurality of electrical contacts disposed on said first substrate and electrically connected to said at least four electrodes;
• and
• at least one auto-on electrical contact disposed on said first substrate and electrically isolated from said at least four electrodes.

A method of making a plurality of test strips, said method comprising:

• forming a plurality of test strip structures on a first insulating sheet, wherein each test strip structure is formed by:
• (a) forming a first conductive pattern on said first insulating sheet, said first conductive pattern including at least four electrodes, said at least four electrodes including a working electrode, a counter electrode, a fill-detect anode, and a fill-detect cathode;
• (b) forming a second conductive pattern on said first insulating sheet, said second conductive pattern including a plurality of electrode contacts for said at least four electrodes, a plurality of conductive traces electrically connecting said at least four electrodes to said plurality of electrode contacts, and an auto-on conductor;
• (c) applying a first dielectric layer over portions of said working electrode and said counter electrode, so as to define an exposed working electrode portion and an exposed counter electrode portion;
• (d) applying a second dielectric layer to said first dielectric layer, said second dielectric layer defining a slot, said working electrode, said counter electrode, said fill-detect anode, and said fill-detect cathode being disposed in said slot;
• (e) forming a reagent layer in said slot, said reagent layer including glucose oxidase and a mediator;
• (f) forming an adhesive layer on said second dielectric layer, said adhesive layer having a break extending from said slot;
• and
• (g) attaching a second insulating sheet to said adhesive layer, such that said second insulating sheet covers said slot but not said electrode contacts or said auto-on conductor;
• and
• separating said plurality of test strip structures into said plurality of test strips, each of said test strips having a proximal end and a distal end, with said slot extending to said proximal end, said proximal end being narrower than said distal end.

A method of making a plurality of test strips, said method comprising:

• forming a plurality of test strip structures on one sheet, each of said test strip structures including:
• (a) a spacer defining a sample chamber;
• (b) a plurality of electrodes formed on said sheet, including a working electrode, a counter electrode, a fill-detect anode, and a fill-detect cathode;
• (c) a plurality of electrical contacts, formed on said sheet and electrically connected to said plurality of electrodes;
• and
• (d) at least one auto-on electrical contact, formed on said sheet and electrically isolated from said plurality of electrodes;
• and
• separating said test strip structures into said plurality of test strips.