Numerical Assessment of a Metal-Insulator-Metal Waveguide-Based Plasmonic Sensor System for the Recognition of Tuberculosis in Blood Plasma

• Published in: Micromachines (Basel) Vol. 14; no. 4; p. 729
• Main Author: Butt, Muhammad A
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25-03-2023; MDPI
• Subjects: Blood plasma; Blood tests; Boundary conditions; Design; Diagnosis; Environmental monitoring; Figure of merit; Gold; Insulators; Light; Medical equipment; metal-insulator-metal waveguide; mode converter; Numerical analysis; Optimization; Plasma; Plasmonics; Refractivity; Sensitivity; Sensors; surface plasmon polariton; Tuberculosis; Waveguides; mode converter; blood plasma; plasmonics; metal-insulator-metal waveguide; tuberculosis; surface plasmon polariton
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi14040729

In this paper, a numerical analysis of a plasmonic sensor based on a metal-insulator-metal (MIM) waveguide is conducted for the detection of tuberculosis (TB)-infected blood plasma. It is not straightforward to directly couple the light to the nanoscale MIM waveguide, because of which two Si
N
mode converters are integrated with the plasmonic sensor. This allows the efficient conversion of the dielectric mode into a plasmonic mode, which propagates in the MIM waveguide via an input mode converter. At the output port, the plasmonic mode is converted back to the dielectric mode via the output mode converter. The proposed device is employed to detect TB-infected blood plasma. The refractive index of TB-infected blood plasma is slightly lower than that of normal blood plasma. Therefore, it is important to have a sensing device with high sensitivity. The sensitivity and figure of merit of the proposed device are ~900 nm/RIU and 11.84, respectively.