What has a surface area the size of a football field, structural features smaller than a pinpoint, and can be custom designed
to detect specific chemicals for integration into a superior sensor? If you guessed functional multiscale materials—also known
as nanoscale materials—you would be correct. What are these amazing materials and how will they revolutionize sensing technology?
Because of the minuscule size of nanoscale materials (1 nm = 10–9 m), their chemical and physical properties differ from those of their bulk counterparts and therefore behave differently.
One of these properties is an ability to be "functionalized" or custom-designed to attract specific molecules; another is
an extremely high surface area tucked into a tiny space.
The unique characteristics of nanoscale materials make them a perfect fit for the sensor world. Integrating them into existing
sensors can increase the devices' sensitivity, selectivity, and speed. In addition, the large surface area and low volume
greatly facilitate sensor miniaturization.
Figure 1. Self-assembled monolayers on mesoporous supports (SAMMS), based on a coating process that makes silica bind to
selected metals; among potential applications: remediation, water treatment, catalysts, and controlled-release markets
Researchers at the Department of Energy's Pacific Northwest National Laboratory (PNNL) are integrating functionalized nanoporous
silica and carbon nano-tubes—both nanoscale materials—into a variety of sensor applications to meet urgent needs in fields
ranging from biomedicine and environmental remediation to national security. The scientists' goal is to lay the foundation
for a miniaturized sensor that uses the smallest sample to detect the smallest concentration of molecules of interest. "Ideally
we'd like to be able to just walk into a room and find one molecule of what we're looking for with a sensor the size of a
pinhead and say, 'it's here' without concentrating or distilling all of the air in the room," says Tim Bays, a PNNL scientist
who works on the functional multiscale materials team.
