A Lossy Mode Resonance optical sensor using silver nanoparticles-loaded films for monitoring human breathing

作者：Rivero Pedro J^*; Urrutia A; Goicoechea J; Matias I R; Arregui F J

来源：Sensors and Actuators B: Chemical , 2013, 187: 40-44.

DOI：10.1016/j.snb.2012.09.022

• Silver nanoparticles (Ag-NPs)
• Lossy Mode Resonances (LMR)
• Humidity sensing

This work is focused on the fabrication of a human breathing sensor based on the in situ synthesis of silver nanoparticles (Ag-NPs) inside a polymeric coating previously deposited on an optical fiber core by means of the Layer-by-Layer self-assembly. The Ag-NPs were created using a synthesis protocol consisting of a loading step of the Ag+ cations into the polymeric film and a further reduction step using dimethylamine borane (DMAB). The morphology and distribution of the Ag-NPs inside the polymeric coating have been studied using atomic force microscopy (AFM). Furthermore, UV-VIS spectroscopy and energy dispersive X-ray (EDX) were also used to confirm the synthesis of the Ag-NPs within the resultant coating. The amount of Ag-NPs increases when the number of loading/reduction cycles is higher. Therefore the incorporation of the Ag-NPs affects the refractive index of the overlay promoting the observation of a resonant attenuation band in the infrared region (NIR), known as Lossy Mode Resonance (LMR), which can be used as a sensing signal to monitor the human breathing. The quality of the device has been experimentally tested with good sensitivity (0.455 nm per RH%) and fast response time (692 ms and 839 ms for rise/fall).

• 出版日期2013-10