Sensitive Hemoglobin Concentration Sensor Based on Graphene-Plasmonic Nano-structures.

Area of Science:

• Nanophotonics
• Biomedical Sensing
• Materials Science

Background:

• Accurate hemoglobin concentration measurement is crucial for diagnosing various medical conditions.
• Plasmonic sensors offer high sensitivity for detecting biomolecules.
• Graphene's unique properties can enhance optical sensor performance.

Purpose of the Study:

• To propose and investigate novel graphene-plasmonic sensor structures for effective hemoglobin concentration detection.
• To optimize sensor performance by exploring different material combinations and structural designs.
• To evaluate the sensor's sensitivity as a refractive index bio-sensor.

Main Methods:

• Fabrication of five individual half-cylindrical rod-based sensor structures using layers of gold (Au), silver (Ag), silicon dioxide (SiO2), and graphene.
• Investigation of the impact of varying graphene layer thicknesses and chemical potential on absorption characteristics.
• Analysis of the role of additional gold layers in enhancing electromagnetic wave confinement and absorption.
• Characterization of the structures as refractive index bio-sensors.

Main Results:

• The proposed graphene-plasmonic structures demonstrate effective detection of hemoglobin concentrations.
• Optimized structures show improved absorption peak values and wavelengths.
• The final proposed structure achieves unity absorption, indicating high efficiency.
• A sensitivity factor of 570 nm/RIU was achieved for hemoglobin concentration detection.

Conclusions:

• Graphene-plasmonic hybrid structures are effective for developing hemoglobin concentration sensors.
• Structural modifications, including material layering and graphene properties, significantly influence sensor performance.
• The developed sensor shows potential for wide applications in bio-sensing, particularly for blood analysis.