MXene (Ti3C2Tx) coated highly-sensitive D-shaped photonic crystal fiber based SPR-biosensor

In this paper, a D-shaped surface plasmon resonance (SPR) refractive index (RI) based biosensor is reported for the earlier detection of various bio-analytes. The lattice of D-shaped photonic crystal fiber (PCF) offers a modified rhombus pattern for cladding air holes. D-shaped PCF is an open channel structure that fundamentally provides ease while interacting with different bio-analytes as compared to closed channels SPRs. A nanoscale MXene (Ti 3 C 2 T x ) layer is introduced with a uniform coating that drastically enhances the sensor’s sensitivity and performance. Finite element method (FEM) is employed to determine dispersion characteristics to acquire the confinement loss spectra as a function of wavelength for various bio-analytes. SPR shifts the resonant interference dip when RI of bio-analytes changes. The proposed SPR sensor with Au/ Ti 3 C 2 T x layer exhibits maximum RI sensitivity of 47,260 nm/RIU at an analyte refractive index of 1.42 with a detection resolution of 2.11×10 -6 RIU, which is 1.7 times higher than that of a single Au-layer SPR sensor. Moreover, it detects a wider range of bio-analytes (i.e., 1.30 to 1.43) using a third-order polynomial fitting function corresponding to the wavelength shift. It covers the detection of most known bio-analytes, i.e., cancerous cervical, breast and blood cells, adrenal gland, glucose concentration, proteins, viruses or DNA/RNA, etc. • The modified rhombus pattern of lattice for cladding air holes in a D-shaped photonic crystal fiber is proposed to produce surface plasmon resonance sensor • Finite element method is employed to obtain an analytical solution to promote the sensor for biosensing applications. • The proposed sensor is an open channel structure that fundamentally provides ease while interacting with different bio-analytes as compared to closed channels surface plasmon resonance sensors. • A nanoscale MXene (Ti 3 C 2 T x ) layer is introduced with a uniform coating that drastically enhances the sensor’s sensitivity and performance. • The sensor exhibits maximum refractive index sensitivity of 47,260 nm/RIU at an analyte refractive index of 1.42 with a detection resolution of 2.11×10 -6 RIU, which is 1.7 times higher than that of a single Gold-layer SPR sensor. • The sensor is capable to detect a wide range of bio-analytes, i.e., 1.30 to 1.43, which covers the detection of most known bio-analytes, i.e., cancerous cervical, breast and blood cells, adrenal gland, glucose concentration, proteins, viruses or DNA/RNA, etc.