Lossy mode resonance sensors based on nanocoated multimode-coreless-multimode fibre

In this work it is proved the ability to obtain lossy mode resonances (LMRs) in the transmission spectrum with multimode-coreless-multimode fibre optic structure coated with tin oxide on the coreless segment. The devices were characterized as a function of the surrounding medium refractive index and sensitivities of 7346.93 nm/RIU and 708.57 nm/RIU were attained for the first and the second LMR respectively. As an application proof of this technology, one of the devices was biofunctionalized and used for detecting goat anti-mouse IgG in concentrations ranging from 1 to 40 mg/L, with a limit of detection of 0.6 mg/L. This proves the ability of this simple structure to be used for biological, chemical or environmental applications.