Enhanced Optical Sensitivity of Polyvinyl Alcohol-Reduced Graphene Oxide Electrospun Nanofiber Coated Etched Fiber Bragg Grating Sensor for Detection of Myoglobin a Cardiac Biomarker

Etched fiber Bragg grating (eFBG) sensors have shown to be highly sensitive with the capability of giving accurate real-time response to a variety of measurands such as pressure, gas, biomolecules, to name a few. These sensors have not shown their mettle as competitive products mainly due to nonreproducibility in results and inefficiency in upscaling for large-scale production; the main reason being nonuniform and complicated coating procedures. Herein, the enhancement in refractive index (RI) sensitivity (approximate to 4 times) obtained with electrospinning of polyvinyl alcohol-reduced graphene oxide (PVA-rGO) nanofibers onto eFBG sensor using a customized target and a unique sandwich arrangement is demonstrated. The enhancement in RI sensitivity has led to a lower detection limit and increased sensitivity and linear range for a case study using myoglobin (Mb), an early-stage cardiac biomarker with high reproducible results (standard error <=+/- 2.3%). rGO embedded PVA nanofiber electrospun onto an eFBG sensor (PVA-rGO sensor) is the first of its kind and has significant importance in developing cost-effective, label-free, multianalyte, portable, real-time, point-of-care (POC) kits at ambient conditions.