THE ENHANCEMENT OF SURFACE PLASMON RESONANCE SENSOR PERFORMANCE MODIFIED BY GRAPHENE FOR HEAVY METALS DETECTION

• Main Author: Ro'idah Fitriani, Rana
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/39551
• Institution: Institut Teknologi Bandung

Surface plasmon resonance (SPR) sensor is an alternative method to detect heavy metal contamination of the environment. SPR sensor measures the SPR angle, which depends on the refractive index of the medium around gold surface of the sensor chip. Sensitivity enhancement of a surface plasmon resonance sensor can be achieved by surface functionalization of gold by the addition of graphene. In this study, several experiments have been conducted to determine the sensitivity of graphene-based SPR sensor. Deposition of graphene on the gold layer was carried out by spin coating method. Graphene adsorbs molecules of heavy metal and increases the refractive index of medium around the surface of sensor chip, so that the obtained measurement results from SPR sensors depict a positive shift of SPR angle toward higher values that correspond to a higher concentration of heavy metal. Sensitivity of the SPR sensor is determined by the ratio of the shift in SPR angle to the change in heavy metal concentration. Graphene thickness affect the sensitivity of the SPR sensor. As the thickness of graphene increases, sensitivity also increases until the thickness reaches optimum value, then decreases. Based on experiment results in this study, the most sensitive graphene-based SPR sensor is the one with graphene thickness of 0.9 nm. Performance tests of three different solutions, namely Pb, Zn, and Cu solutions showed that graphene based SPR sensor were more sensitive in Pb detection.