Low-cost, smartphone-based spectrometer could tell you whether something is good to eat or not [View all]

by Mihai Andrei July 19, 2024 Time: 5 mins read
Edited and reviewed by Zoe Gordon

Imagine knowing which berry or mushroom is safe to eat during a hike or swiftly detecting pathogens in a hospital setting that would traditionally require days to identify. Now, imagine all this, plus the identification and detection of drugs, chemicals, and biological molecules invisible to the human eye — all through a smartphone-based instrument,

Phone-based spectrometry
Dr. Peter Rentzepis, a professor in the Department of Electrical and Computer Engineering at Texas A&M University, has developed and patented a handheld system that works like a Raman spectrometer. A Raman spectrometer works by using a laser to interact with the molecular vibrations within a sample. When light from the laser hits the molecules, it scatters in various directions. Most of this light scatters elastically, meaning it retains the same energy. However, a small portion scatters inelastically, meaning it changes energy levels, and this is known as Raman scattering. The Raman spectrometer measures these shifts in energy to provide a molecular fingerprint of the substance.

The system integrates lenses, a diode laser, and a diffraction grating — a small, thin, square surface that scatters light. It uses a cell phone camera to record the Raman spectrum. And it uses the computer’s processing power to derive the chemical composition and molecular structure based on this spectrum. It’s small enough to put in your pocket, says Rentzepi, and particularly useful when large-scale spectrometers are unavailable or too expensive to use.

Traditional Raman spectrometers are expensive, costing thousands of dollars. In contrast, Rentzepis’ invention can be produced at a significantly lower cost and identifies materials quickly.

More:
https://www.zmescience.com/future/low-cost-smartphone-based-spectrometer-could-tell-you-whether-something-is-good-to-eat-or-not/