Nanosensors for analysis of a single cell

Abstract

Submicron fiber-optic biosensors have been developed and used to measure toxic chemicals within single cells. These sensors are fabricated by pulling the distal-end of an optical fiber to a diameter of less than one micron and coating them with antibodies to selectively bind the species of interest. This paper describes the use of these fibers to selectively measure the concentration of benzo[a]pyrene tetrol, a metabolite of benzo[a]pyrene, within individual cells of two different cell lines, human mammary carcinoma cells and rat liver epithelial cells. The results from these measurements have been used to evaluate the analytical figures of merit of these sensors such as detection limits, which were found to be 0.64 +/- 0.17 X 10⁻¹¹ M for BPT. In addition, measurements were performed both extracellularly and intracellularly, and an increase in variation of approximately 4% was determined for the intracellular measurements, relative to the extracellular measurements.