The objective of the proposed work is to design a biosensor that monitors hemoglobin (Hb) concentration using the combination of nanolayer, i.e., barium titanate (BaTiO 3) and antimonene based on surface plasmon resonance (SPR) technique. Antimonene is used here as bio-recognition element (BRE) layer to attach the Hb analyte through physical adsorption due to its hydrophilic nature, higher adsorption energy and larger active surface area. The use of BaTiO 3 adlayer (7 nm) just before antimonene is to enhance the refractive index (RI) sensitivity up to 1.90 times for the proposed SPR biosensor. The reason behind sensitivity enhancement is its high dielectric constant which enhances the electromagnetic field with in analyte medium. The performance of the biosensor is demonstrated with performance parameters namely sensitivity, detection accuracy (DA), figure of merit (FOM) and resolution. The proposed biosensor has potential to achieve much higher performance in terms of RI sensitivity of 303.83°/RIU, FOM of 50.39 RIU −1 and resolution of 0.021 g/l in comparison with reported biosensors in the literature for detection of Hb concentration. Thus, based on the obtained results one can say that the proposed work unlocks a reliable sensing in the field of medical science to detect hemoglobin-related diseases in human being.