A gold/MXene/MOF composite based optical fiber biosensor for haemoglobin detection

Abstract

Surface Plasmon Resonance (SPR) based Optical fiber sensors are ubiquitously used for varied applications in biosensing, food monitoring, water quality, gas sensing due to their simple, low cost, and miniaturised setup. The improvement in the sensitivity of these sensors is a critical challenge. 2-D MXenes are found to provide enhanced sensitivity for plasmonic biosensing because of high hydrophilicity, metallic conductivity, abundance of functional groups for bio conjugation, and wide band optical absorption. Here, we demonstrate the enhancement in the sensitivity of MXene (Ti3C2) coated multimode SPR optical fiber sensor by resolving the response of two different Refractive indices values. The effect of MXene concentration and the number of layers has been investigated. The introduction of MXene has caused a noticeable enhancement in the sensor’s sensitivity. Further, Ti3C2 has also been combined with Terbium based metal-organic framework (Tb-BTC) to prepare a sensor for haemoglobin. Tb-BTC binds to the iron fragment of haemoglobin assisting a selective response from the above developed SPR sensor. The response of the sensor for haemoglobin has been studied from 100 – 500 μg/mL. The sensor is also specific even in co-presence of other analytes such as immunoglobin, glucose, uric acid, and bovine serum albumin.