Real-time, label-free, and fast monitoring of cell viability by an optical fiber-based microcantilever biosensor.

To overcome the difficulty of effective, real-time, and rapid detection of cell activities in biological experiments, an optical fiber-based microcantilever biosensor is designed and prepared using microelectromechanical system (MEMS) technology. The cantilever beam is integrated with a single-mode fiber to form a Fabry-Perot interferometer (FPI). After the cells attach to the cantilever, changes in the resonance wavelengths of the interference spectra are monitored to detect the cantilever fluctuations caused by cell movements. We report for the first time, to the best of our knowledge, the use of optical fiber interference demodulation detection to assess cell viability continuously and directly in the cell culture medium. The device delivers excellent performance in detecting the effects of doxorubicin on the activity of HeLa cells. The high detection sensitivity stems from the cantilever with a spring constant of 0.12 N/m. It takes about 2 hours to assess the reactions between cancer cells and anticancer drugs. This breakthrough technology establishes a new paradigm for high-throughput drug screening, dynamic resistance evaluation, and mechanobiological studies, with significant potential in clinical diagnostics and personalized therapeutics development.