Technologies combined into portable spectrometer to rapidly detect harmful materials

A smartphone camera and Raman spectrometer have been combined into a device that identifies drugs, chemicals and biological molecules that are invisible to the human eye.

A smartphone records the Raman spectrum of an unknown material (an ethanol solution, in this case) for further analysis
A smartphone records the Raman spectrum of an unknown material (an ethanol solution, in this case) for further analysis - Texas A&M University Engineering

Dr Peter Rentzepis, a professor in the Department of Electrical and Computer Engineering at Texas A&M University, holds a patent for the hand-held smartphone -based Raman spectrometer system. Rentzepis’ invention allows the user to make non-invasive identifications of potentially harmful chemicals or materials in the field. 

This new Raman spectrometer system integrates lenses, a diode laser and a diffraction grating in combination with a smartphone camera to record the Raman spectrum. Peaks in the spectrum provide detailed data about the chemical composition and molecular structure of a substance, depending on their intensities and positions.

To use the device, a smartphone is placed behind the transmission grating with the camera facing the grating, ready to record the Raman spectrum. A laser shoots a beam into a sample of unknown material, such as a bacterium, on a slide. The camera records the spectrum, and when paired with an appropriate smartphone application/database, this handheld instrument can enable rapid materials identification on site.

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Previously, the process of identifying unknown substances involved extensive sampling of biological material and laboratory analysis. While traditional Raman spectrometers cost up to thousands of dollars, Rentzepis’ invention can reportedly be made at a significantly lower cost and can identify materials at a significantly quicker speed.

“It’s a small device that can tell you the composition of a particular system, material or sample,” Rentzepis said in a statement. “You can even have it in your pocket.”

Fellow inventors are former graduate students Dr. Dinesh Dhankhar, a system engineer at Thermo Fisher Scientific, and Anushka Nagpal, a process engineer at Intel Corporation.

Funding for this research is administered by the Texas A&M Engineering Experiment Station (TEES), the official research agency for Texas A&M Engineering.