Surface ion imprinted nano-fibre Bragg grating for detection of multiple heavy metal ions

Heavy metal (HM) pollution is one of the most serious environmental problems undermining global sustainability. Presence of HM in water further contaminates soil, enters food cycle, and finally accumulates in brains, kidneys, livers, and stomach, undermining human health. There is a market gap in low-cost on-line HM sensor, and this is needed to measure HM in-situ on-demand to reduce, mitigate or control environment contamination. Hence, an innovative solution is required to exploit the advantages of optical fibre sensors (OFS), in developing a compact, cost effective, fast, robust, and portable sensor for the accurate detection of several HM ions, simultaneously. In this project, besides the key focus of training the Researcher, the innovative potential of multiplexing OFS will be additionally combined with an enhanced light-matter interaction in tapered nano optical fibre (NOF) to increase its sensitivity and thus create a new generation of OFS to detect multiple HM ions simultaneously. Subsequently, wavelength selective grating will be inscribed on the NFBG along with Au film coated to enhance sensitivity. Additionally, graphene oxide (GO), and ion imprinted polymer-chitosan (IIP-CS) will be coated, which will not only improve the selectivity, but the added polymer will also strengthen the NFBG. In this project, the Researcher will numerically optimize the structural parameters and study the effect of fabrication tolerances of the OFS by using the finite element method. Subsequently, optimised OFS will be fabricated by a using laser induced grating fabrication technique and the Au/GO/(Pb2+, Cu2+, and Cr2+)/IP-CS will be coated on 3 concatenated sections of the NFBG surface by using dip coating method for simultaneous detection of Pb, Cu and Cr. The project aims to exploit multiplexing capability of OFS, which will use only a single interrogator and thus produce a cost-effective, sensitive, fast and on-line HM ions to provide safe water and safer environment.