Systems for analyte detection
This disclosure provides a system component and method for analysis of airborne analytes by absorbing the analytes into a liquid and interrogating the liquid with an analytical instrument. In some examples, a cartridge with a microfluidic chip contains a vessel of a colloidal solution of nanostructured particles in a liquid. The vessel is broken, releasing the solution into microfluidic containers on the chip. Air having analytes is passed over the chip leading to absorption of airborne analytes into the solution. The analytes bind with the nanostructures and are detected optically. Techniques are disclosed for filling the vessel in a way that maintains the efficacy of the solution until it is needed for measurement.
1. A system for detecting analytes, the system comprising:
a cartridge formed from an inert polymeric material, the cartridge having a vapor inlet port to an airflow manifold and a vacuum exhaust port from the manifold;
a microfluidic chip installed in a first chamber of the cartridge, the chip exposed to the airflow manifold and the chip including at least one microfluidic container with at least one free surface;
an optical window in the cartridge for optical interrogation of the microfluidic container; and,
a colloid vessel disposed in a second chamber of the cartridge, the colloid vessel containing a colloidal solution comprising Surface Enhanced Raman Scattering (SERS) probes in a liquid, and the second chamber being in fluid communication with the first chamber via a fluid passageway.
2. The system of claim 1 , wherein the colloid vessel is a glass ampoule.
3. The system of claim 2 , the cartridge having an access port disposed to allow a vessel breaking tool to break the glass ampoule, and the fluid passageway being constricted such that upon breaking of the ampoule capillary forces draw the colloidal solution, but not glass shards of the ampoule, through the constricted passageway to the microfluidic container.
4. The system of claim 1 , wherein the colloid vessel is a metal foil packet with size from about 1 mm to 15 mm.
5. The system of claim 4 , the cartridge having an access port disposed to allow a vessel breaking tool to puncture the metal foil packet such that upon puncturing of the foil packet colloidal solution flows through the fluid passageway to the microfluidic container.
6. The system of claim 1 , the SERS probes being nanostructured particles.
7. The system of claim 1 , the inert polymeric material being polytetrafluoroethylene (PTFE).
8. The system of claim 1 , the inert polymeric material being perfluoroalkoxy (PFA).
9. The system of claim 1 , the cartridge including ribbed or corrugated surfaces to enable a user to grip it.