Method and device for detection of bioavailable drug concentration in a fluid sample

1. An electrochemical voltammetric sensor device comprising,

a body comprising a first lumen;

a securing body comprising a second lumen;

a flexible circuit comprising a connection end and a sensor end, wherein the flexible circuit comprises a flexible strip of material; wherein the flexible strip of material comprises a first layer and a second layer, wherein the first layer and the second layer comprise polyamide;

the connection end comprising a plurality of vias;

the sensor end comprising an electrochemical sensor, wherein the electrochemical sensor comprises a first array of electrodes, wherein the first array of electrodes are electrically connected to the vias using conductive traces, wherein the first array of electrodes comprises a water-immiscible coating that surrounds the first array of electrodes, wherein the coating partitions a hydrophobic drug from a fluid sample;

wherein the body resides within the second lumen of the securing body, wherein an upper surface of the flexible circuit is adjacent and conforms to an interior circumferential curvature of the second lumen,

wherein a lower surface of the flexible circuit is adjacent and conforms to an exterior circumferential curvature of the body;

the securing body comprising a first opening positioned above the first array of electrodes,

wherein the first opening exposes the first array of electrodes to the fluid sample.

2. The electrochemical voltammetric sensor device of claim 1 , wherein the flexible strip of material comprises a third layer between the first and the second layer, wherein the third layer comprises adhesive and the conductive traces.

3. The electrochemical voltammetric sensor device of claim 1 , wherein pins of a mating connector pass through corresponding vias of the connection end, wherein the pins and the connection end are joined by soldering the pins to the corresponding vias.

4. The electrochemical voltammetric sensor device of claim 1 , wherein the mating connector couples the vias to a potentiostat circuit which controls voltage and current supplied to the electrochemical sensor.

5. The electrochemical voltammetric sensor device of claim 1 , wherein the electrochemical sensor comprises a second array of electrodes, wherein the second array of electrodes are electrically connected to the vias using conductive traces, wherein the second array of electrodes comprises the water-immiscible coating that surrounds the second array of electrodes, wherein the coating partitions the hydrophobic drug from the fluid sample.

6. The electrochemical voltammetric sensor device of claim 1 , the securing body comprising a second opening positioned above the second array of electrodes, wherein the second opening exposes the second array of electrodes to the fluid sample.

7. The electrochemical, voltammetric sensor device of claim 6 , wherein the hydrophobic drug is oxidized within the coating, wherein at least one of the first array of electrodes and the second array of electrodes measure an oxidation/reduction current within the coating, and wherein the measured oxidation/reduction current correlates to the amount of the hydrophobic drug partitioned into the coating.

8. The electrochemical, voltammetric sensor device of claim 1 , wherein the coating further comprises a membrane resistance controlling component selected from the group consisting of lipophilic electrolytes, tetradodecyl ammonium-tetrakis(4-chlorophenyl) borate (ETH500), and bis(triphenylphoranylidene) ammonium tetrakis[3,5-bis(trifluoromethyl) phenyl] borate (BTPPATFPB); a biocompatibility enhancing component selected from the group consisting of nitric-oxide releasing sol-gel materials, N-(6-aminohexyl)aminopropyltrimethoxysilane, and balanced isobutyltrimethoxysilane diazeniumdiolate; or both.

9. The electrochemical, voltammetric sensor device of claim 1 , wherein the coating comprises PVC, o-NPOE, and TDATPFPB.

10. The electrochemical, voltammetric sensor device of claim 1 , wherein the coating is less than about 200 μm thick.

11. An electrochemical voltammetric sensor device comprising, a body comprising a first lumen;

a securing body comprising a second lumen;

a flexible circuit comprising a connection end and a sensor end;

the connection end comprising a plurality of vias; wherein pins of a mating connector pass through corresponding vias of the connection end, wherein the pins and the connection end are joined by soldering the pins to the corresponding vias;

the sensor end comprising an electrochemical sensor, wherein the electrochemical sensor comprises a first array of electrodes, wherein the first array of electrodes are electrically connected to the vias using conductive traces, wherein the first array of electrodes comprises a water-immiscible coating that surrounds the first array of electrodes, wherein the coating partitions a hydrophobic drug from a fluid sample;

wherein the body resides within the second lumen of the securing body, wherein an upper surface of the flexible circuit is adjacent and conforms to an interior circumferential curvature of the second lumen;

wherein a lower surface of the flexible circuit is adjacent and conforms to an exterior circumferential curvature of the body; and

wherein the securing body comprises a first opening positioned above the first array of electrodes, wherein the first opening exposes the first array of electrodes to the fluid sample.

12. The electrochemical voltammetric sensor device of claim 11 , wherein the flexible strip of material comprises a first layer and a second layer, wherein the first layer and the second layer comprise polyamide.

13. The electrochemical voltammetric sensor device of claim 12 , wherein the flexible strip of material comprises a third layer between the first and the second layer, wherein the third layer comprises adhesive and the conductive traces.

14. The electrochemical voltammetric sensor device of claim 11 , wherein the mating connector couples the vias to a potentiostat circuit which controls voltage and current supplied to the electrochemical sensor.

15. The electrochemical voltammetric sensor device of claim 11 , wherein the electrochemical sensor comprises a second array of electrodes, wherein the second array of electrodes are electrically connected to the vias using conductive traces, wherein the second array of electrodes comprises the water-immiscible coating that surrounds the second array of electrodes, wherein the coating partitions the hydrophobic drug from the fluid sample.

16. The electrochemical voltammetric sensor device of claim 11 , the securing body comprising a second opening positioned above the second array of electrodes, wherein the second opening exposes the second array of electrodes to the fluid sample.

17. The electrochemical voltammetric sensor device of claim 16 , wherein the hydrophobic drug is oxidized within the coating, wherein at least one of the first array of electrodes and the second array of electrodes measure an oxidation/reduction current within the coating, and wherein the measured oxidation/reduction current correlates to the amount of the hydrophobic drug partitioned into the coating.

18. The electrochemical voltammetric sensor device of claim 11 , wherein the coating further comprises a membrane resistance controlling component selected from the group consisting of lipophilic electrolytes, tetradodecyl ammonium-tetrakis(4-chlorophenyl) borate (ETH500), and bis(triphenylphoranylidene) ammonium tetrakis[3,5-bis(trifluoromethyl) phenyl] borate (BTPPATFPB); a biocompatibility enhancing component selected from the group consisting of nitric-oxide releasing sol-gel materials, N-(6-aminohexyl)aminopropyltrimethoxysilane, and balanced isobutyltrimethoxysilane diazeniumdiolate; or both.

19. The electrochemical voltammetric sensor device of claim 11 , wherein the coating comprises PVC, o-NPOE, and TDATPFPB.

20. The electrochemical voltammetric sensor device of claim 11 , wherein the coating is less than about 200 μm thick.