Solid phase microextraction (SPME) is a demonstrated and attractive method for sampling and pre-concentrating trace level analytes. SPME was first successfully developed as a polymer coating on silica fibers in the early 1990s.  Due to its broad applicability and sensitivity, it has been utilized widely in a variety of fields. Since polymer phases can be blended, different surface properties of polymers can simply be coated and tailored onto a single fiber. However, some drawbacks of polymer SPME can limit their applications. They are unstable with some solvents, have insufficient mechanical strength, and tend to degrade at high operating temperatures. Additionally the coatings are occasionally stripped, and they suffer from contaminations and unstable coatings on new fibers.

Researchers at PNNL have developed an advanced SPME structure that surpasses the current standard in the capture of trace-level vapor phase analytes. The novel SPME device uses a unique binding process to secure a nanoporous thin film of high surface-area sorbent materials to a rigid wire support. Further, novel selective and highly affinitive surface chemistries can be installed onto the nanoporous silica for enhanced selectivity and capture of target analytes. This functionalization allows for increased collection of the analyte, for example, adsorbing the explosive DNT eight times better then commercial SPME fibers. This technology has value by lowering the detection limits of trace analytes while providing a far more robust field sampling unit than currently commercially available. By design, the improved SPME device fits into existing sampling and analytical testing equipment thereby reducing additional equipment costs.