UI and University of Chicago collaborate on nanodiamond sensor research

The University of Iowa, in collaboration with the University of Chicago, is advancing research on nanodiamond sensors to explore their potential in studying cellular environments. These sensors utilize nanodiamonds, which are diamond particles smaller than 100 nanometers, first discovered in 1963 and employed as sensors since the early 2000s.

Nanodiamond sensors operate through impurities known as Nitrogen-Vacancy centers. These occur when a carbon atom in the diamond lattice is replaced by a nitrogen atom adjacent to a vacancy, creating a defect with an electronic spin. Michael Flatté, a theoretical physicist and professor at the University of Iowa, explained that the quantum spin of the electron is crucial for data observation.

Flatté likened the process to a spinning top, which changes its rotation frequency based on environmental factors like gravity. When a magnetic field is applied to the electron in the Nitrogen-Vacancy center, it precesses around the field's direction. The precession rate, influenced by the magnetic field's strength, enables researchers to analyze specific environmental properties.

In 2025, University of Iowa physicist Denis Candido and Flatté enhanced the sensors' accuracy by applying a silica coating to the nanodiamonds. This coating reduced surface charge interference, improving sensor clarity and reliability in disease detection. Candido noted that the electrons in the vacancy have discrete energy levels responsive to external stimuli such as magnetic fields, temperature, and pH.

Candido described the sensor operation involving a continuous low-power green laser through the diamond, measuring emitted photoluminescence. Changing microwave frequencies are applied, and when they match the differences between spin states, the Nitrogen-Vacancy center's spin state alters, affecting fluorescence.

Uri Zvi, a postdoctoral fellow at the University of Chicago, highlighted the sensors' capability for enhanced analysis of individual cells. He noted that classical sensors struggle with real-time biophysical property measurements of cells, whereas nanodiamond sensors excel in this area.

The ongoing research aims to validate the accuracy and clarity of these measurements. Zvi stated that the objective is to understand and interpret shifts in zero field splitting as the electric field changes within the diamond, correlating them with cellular environmental changes, particularly inflammation.

While the sensors' ability to detect specific diseases like cancer remains unproven, the goal is to measure energy rate changes and their correlation with inflammation or other cellular changes. Zvi mentioned that future studies will focus on identifying environmental factors influencing cellular inflammation.