MIT researchers enhance fluorescent sensor signals, providing a rare sight inside living cells.

Engineering advance allows particles to be placed deeper within biological tissue, which could aid with cancer diagnosis or monitoring.

Fluorescing nanosensors' signal could now be significantly improved thanks to MIT engineers' discovery. The scientists demonstrated that they could implant sensors into tissue as deep as 5.5 cm and still receive a good signal.

Enhanced fluorescence

Fluorescent sensors, which can be used to label and image a wide variety of molecules, provide a unique glimpse inside living cells. However, they typically can only be used in cells grown in a lab dish or in tissues close to the body’s surface, since their signal is lost when they are implanted too deeply.

MIT engineers have now devised a solution to overcome that limitation. Using a novel photonic technique they invented for exciting any fluorescent sensor, they were able to significantly improve the fluorescent signal. With this approach, the scientists showed they could implant sensors as deep as 5.5 centimeters (2.2 inches) in tissue and still get a strong signal.

According to the researchers, this type of technology might allow fluorescent sensors to be used to track specific molecules inside the brain or other tissues deep within the body, for medical diagnosis or monitoring drug effects.