An international team of researchers from the Nonlinear Dynamics and Optical Fibers Group Thomas Allsop (first author) and Juan Diego Ania Castañón, has developed a fiber optic plasmonic biosensor that for the first time allows the detection outside the laboratory of Bisphenol A in very low concentrations.
This pollutant, present in many types of plastics for more than 50 years needs very little concentration to cause imbalances in the hormonal system, but its low molecular weight makes its detection difficult.

The biosensor consists of a series of gold nanoantennas over a length of 2.3 centimeters of optical fiber. Molecules sensitive to the contaminant that is to be detected are immobilized on these nanoantennas. The behavior of the light passing through the fiber depends on the resonance frequency of the collective oscillations of the conduction electrons or "surface plasmons", which in turn depends on the concentration of the pollutant. This allows us to accurately measure this concentration. The work has been published in the journal Biosensors & Bioelectronics (link to the publication)