Point of Care Detection of Blood Electrolytes and Glucose Utilizing Nano-Dot Enhanced Plasmonic Biosensor

To satisfy the requirements of label-free detection, low cost, fast response of a lab-on-chip biosensor, a nanodot enhanced metal-insulator-metal ( MIM ) waveguide based refractive index sensor coupled with three rectangular cavities, is proposed in this work. Numerical investigation of the transmission spectra, employing the finite element method ( FEM ), exhibits a linear correspondence with the refractive index, which is used to sense the unknown materials. Imposing a sequential optimization of the structural parameters and enhancing light-matter interaction by loading nanodots at the high {E} -field confined areas, desired sensitivity ( {S} ) and figure of merit ( FOM ) are upgraded to 7564\,\, nmRI{U^{ - 1}} and 120, respectively. Additionally, the maximum temperature sensitivity of 3.40\,\, nm{}^{0}{C^{ - 1}} operating from 20{}^{0} {C} to 70{}^{0} {C} is also recorded for ploydimethylsiloxane ( PDMS ) sensing media. Prior to the selective detection of Na^{\mathrm{ +}} , K^{\mathrm{ +}} , and glucose concentration in the human blood, a sample preparation model combining purification, molecular separation, and concentration enhancement is proposed. Furthermore, a refractive index model is developed that exposes a maximum shift of 0.83 nm , 1.23 nm , and 8.72 nm of the transmittance peak for the concentration variation of 1\,\, mgd{L^{ - 1}} in Na^{\mathrm{ +}} , K^{\mathrm{ +}} , and glucose solution easily differentiable by the modern spectrometer. With such excellent performance metrics, compact size, and simple to use features, the proposed sensor is expected to bring a notable solution in the point-of-care detection.