Cartridges for integrated BAW biosensors and methods for using the same

1. A cartridge for handling and sensing a sample fluid, the cartridge comprising:

a sensor comprising a bulk acoustic wave (BAW) resonator having a sensing surface;

a sample port for introducing the sample fluid into the cartridge;

a fluid flow path from the sample port to the sensor for carrying the sample fluid introduced into the sample port across the sensing surface of the resonator, the fluid flow path comprising:

a sample reservoir defining a proximal portion of the fluid flow path and defining an inner surface, the sample reservoir having a proximal end connected to the sample port, a proximal region adjacent the proximal end, a distal end, a distal region adjacent the distal end, and a volume extending between the proximal end and the distal end;

a sensing portion downstream of the sample reservoir and extending across the sensing surface of the resonator, wherein the sensing surface of the resonator defines at least a portion of a surface of the sensing portion;

a valve disposed in the distal region of the sample reservoir;

a first fluid port for introducing a first fluid into the cartridge;

a first fluid channel having a proximal end connected to the first fluid port and a distal end connected to the distal region of the sample reservoir via the valve, wherein the first fluid channel is in fluid communication with the sensing surface;

a second fluid port for introducing a second fluid into the cartridge; and

a second fluid channel having a proximal end connected to the second fluid port and a distal end connected to the proximal region of the sample reservoir,

wherein the first fluid and the second fluid are the same or different and do not comprise a sample, and wherein the first fluid port and the second fluid port are constructed to couple with an external pump.

2. The cartridge of claim 1 , wherein the valve is disposed at the distal end of the sample reservoir.

3. The cartridge of claim 1 , wherein the valve comprises a hydrophobic valve.

4. The cartridge of claim 1 , wherein the valve comprises a hydrophobic coating of the fluid flow path.

5. The cartridge of claim 1 , wherein the sensor comprises a second BAW resonator having a sensing surface, wherein the sensing surface of the second resonator defines at least a portion of the surface of the sensing portion of the flow path.

6. The cartridge of claim 1 , wherein the volume of the sample reservoir is from about 1 μL to about 20 μL.

7. The cartridge of claim 1 , wherein the sample reservoir volume is defined by walls having a hydrophilic surface.

8. The cartridge of claim 7 , wherein the walls comprise a hydrophilic coating.

9. The cartridge of claim 1 , wherein the first fluid port and the second fluid port are constructed to couple with an external fluid reservoir.

10. The cartridge of claim 1 , wherein the first fluid port and the second fluid port comprise a first valve and a second valve, respectively.

11. The cartridge of claim 1 , wherein the fluid flow path comprises a mixing region downstream of the sample reservoir.

12. The cartridge of claim 11 , wherein the mixing region comprises one or more static features constructed to induce mixing in the fluid flow path.

13. The cartridge of claim 12 , wherein the one or more static features comprise a protrusion narrowing an inside diameter of the fluid flow path.

14. The cartridge of claim 1 , wherein the first and second fluid channels are microfluidic channels.

15. The cartridge of claim 1 , wherein the sensing portion of the fluid flow path is a microfluidic channel.

16. The cartridge of claim 1 , wherein the sample port comprises a closure.

17. A method of sample handling and sensing using a cartridge,

the cartridge comprising:

a sample port for introducing a sample fluid into the cartridge, the sample port being connected to a sample reservoir having a proximal end, a proximal region adjacent the proximal end, and a distal end opposite of the proximal end;

a sensor platform comprising a bulk acoustic wave (BAW) resonator and a fluid flow path comprising a sensing region extending across a sensing surface of the BAW resonator; and

a fluid valve between the distal end of the sample reservoir and the sensing region,

a first fluid port for introducing a first fluid into the cartridge, the first fluid port being connected to a first fluid channel, the first fluid channel being connected to the sample reservoir in the distal region via the fluid valve, and the first fluid channel being in fluid communication with the sensing surface;

a second fluid port for introducing a second fluid into the cartridge, the second fluid port being connected to the sample reservoir in the proximal region via a second fluid channel;

wherein the first fluid and the second fluid are the same or different and do not comprise a sample;

the method comprising:

applying the sample fluid to the sample port;

injecting a first volume of the first fluid through the first fluid port to cause the first fluid to flow across the sensing surface; and

then injecting a second volume of the second fluid through the second fluid port to drive the sample fluid into the sensing region of the fluid flow path.

18. The method of claim 17 , wherein the first fluid comprises a buffer.

19. The method of claim 17 , wherein the second fluid comprises a buffer or a gas.

20. The method of claim 17 , wherein the sensing portion of the fluid flow path is a microfluidic channel.