Yinfa Ma, Curators’ Teaching Professor of chemistry, and Honglan Shi, an associate research professor of chemistry, are working with colleagues at Clemson University to develop a microscopic fiber optic probe that can detect changes in a single cell. The work is funded through a $567,311 grant from the National Institute of General Medical Sciences of the National Institutes of Health.

Imagine a doctor’s needle that is only 2 to 5 microns in size. When inserted into a cell, the probe’s fluorescent nanomaterial-doped tip is used to detect either the cell’s pH change or corresponding temperature change.

When hit with a laser source attached to the probe, the six strands surrounding the central fiber detect changes in the cell’s reflected fluorescent signal. Researchers then calculate the ratio in two ways: one looks at the peak fluorescent intensity and the reference intensity; the other measures the decay time of the phosphorescence, which is then calculated and correlated with the pH or temperature values.

“Comprehensive understanding of a single cell in response to its biological environment and stimuli is becoming the foundation of many biomedical research fields, including drug development, nanotoxicity study, biomarker discovery, cancer diagnosis and treatment, and many other areas,” Ma says.