Single-cell monitoring using fiberoptic nanosensors

This article is a review on the design, fabrication, and applications of fiberoptic nanosensors for in vivo monitoring of individual living cells. The nanosensors were fabricated with tapered optical fibers with distal ends having nanometer-sized diameters. Bioreceptors, such as antibody, peptides, and nucleic acids, are immobilized on the fiber tips and designed to be selective to target analyte molecules of interest. A laser beam is transmitted into the fiber, producing an evanescent field at the tip of the nanofiber that is used to excite target molecules bound to the bioreceptor molecules. The fluorescence originated from the analyte molecules is detected by a photo-detection system. The advantages and limitations of nanosensors in providing minimally invasive tools to probe subcellular compartments inside individual living cells for health effect studies and medical applications are discussed in detail.