Quantum-Limit-Approaching Chemical Sensing Chip

University at Buffalo, NY

The chip may have uses in food safety monitoring, anti-counterfeiting, and other fields where trace chemicals are analyzed. (Image: Huaxiu Chen, University at Buffalo)

Researchers developed a chemical sensing chip that could lead to handheld devices that detect trace chemicals — everything from illicit drugs to pollution — as quickly as a breathalyzer identifies alcohol. It also may have uses in food safety monitoring, anti-counterfeiting, and other fields where trace chemicals are analyzed.

Using surface-enhanced Raman spectroscopy (SERS), when biological or chemical molecules land on the chip’s surface, some of the captured light interacts with the molecules and is “scattered” into light of new energies. This effect occurs in recognizable patterns that act as fingerprints of chemical or biological molecules, revealing information about what compounds are present.

Because all chemicals have unique light-scattering signatures, the technology could eventually be integrated into a handheld device for detecting drugs in blood, breath, urine, and other biological samples. It could also be incorporated into other devices to identify chemicals in the air or from water, as well as other surfaces.

The work builds upon previous research that involved creating a chip that traps light at the edges of gold and silver nanoparticles. For the new version, the team used four molecules (BZT, 4-MBA, BPT, and TPT) — each with different lengths — in the fabrication process to control the size of the gaps in between the gold and silver nanoparticles. The updated fabrication process is based upon two techniques, atomic layer deposition and self-assembled monolayers, as opposed to the more common and expensive method for SERS chips, electron-beam lithography.

The result is a SERS chip with unprecedented uniformity that is relatively inexpensive to produce. More importantly, it approaches quantum-limit sensing capabilities.

For more information, contact Cory Nealon at This email address is being protected from spambots. You need JavaScript enabled to view it.; 716-645-4614.