The increasing demand for sensors in industry, medicine, environmental monitoring, and even in our own homes, drives the efforts to develop increasingly sensitive techniques to detect biomarkers in extremely low concentrations. For example, reliable laboratory diagnosis has been one of the foremost priorities for promoting public health interventions. For this, a standard clinical verification method is ELISA [1]. Here a color change reaction of enzyme labeled antibodies takes place, which enables the detection of extremely low concentrations. However, ELISA is rather slow and the reaction kinetics cannot be tracked. An alternative optical biosensing method is surface plasmon resonance (SPR) that has evolved to be the standard approach among various label-free optical methods [2]. Biosensors do not require that any material be multiplied to generate a signal, or that the biological sample go through multiple lab processing steps. However, the resonance exploited in plasmon based sensing is governed by the optical properties of the metal film used. This results in missing flexibility in operation wavelength. Furthermore, the resonance width is determined by the metal losses and cannot be narrowed to lower the limit of detection. Many scientists and engineers have put vast efforts into developing optical fibers, which made it a practical communication medium and changed the world. Nowadays, optical fibers connect the globe via internet, which is currently the backbone of our information-driven society and economy. Large-scale applications, not only in telecommunication [3], but also in sensing applications due to their multiple advantages compared to conventional electric sensors [4,5], becoming increasingly important for applications in industrial process and quality control, biomedical analysis, and environmental monitoring [6–9]. Fiber optics research has regained substantial interest during recent years by the integration of materials that are traditionally not used in fiber optics [10-12]. The combination of fiber–optic-based platforms with the nanotechnologies is opening the opportunity for the development of high-performance photonic devices. The generation of optical resonances by means of the deposition of dielectric nanofilms on special optical fiber allows measuring precisely and accurately surface refractive index changes. This approach enhances the light-matter interaction in a strong way, thus turning out to be more sensitive compared to other optical technology platforms. In this postdoc project, it is proposed to pursue the investigations that the research group has been carrying out on Bloch surface wave (BSW) resonance, different from those reported in optical fibers (SPR and lossy mode resonance), for the development of wavelength-based resonance biosensors. BSWs are waves that propagate at the interface between a homogeneous dielectric medium and an abruptly terminated photonic crystal (PC), typically a periodic dielectric multilayer, often referred to as one dimensional PC (1DPC). Here, it is considered a structure based on geometrically modified commercial optical fibers with a PC, seeking to develop an affordable and low-cost platform.