Optical fiber antenna employing quantum dots as gas molecule receptors

Abstract

The discovery of odorant receptors inspiring researchers to refine the artificial olfactory system with the better design of receptor function and transducer function. Colloidal quantum dots (CQDs) offer an abundance of available surface area for chemical and electronic interactions, making them ideal receptors for gas molecules. In this paper, we propose optical fiber antenna (OFA) that mimic the structure and function of biological antenna by using CQDs as the artificial receptors for gas molecules. The charge transfer between the gas molecules and quantum dots is designed to modulate the interaction between the quantum dot solids and light through the variation of refractive index (RI) of quantum receptors. Specifically, lead sulfide (PbS) CQDs serving as NO2 receptors were deposited on the optical structure for comparison. The solution-processability of CQDs enable their uniform and conformal coating on the fiber. The OFA exhibited a sensitivity of 35 pm ppm−1 for NO2 sensing at room temperature with the detection limit estimated to be 1 ppb. The proof of OFA concept may pave the way to artificial olfactory networking and will benefit for the development of high precise, large scale, real time distributed gas monitoring application beyond human olfaction.