Improvement of fiber optic based localized surface plasmon resonance sensor by optical fiber surface etching and Au capping

Abstract Fiber optic based localized surface plasmon resonance (FO-LSPR) sensor is one of the biosensors that detects specific biomolecules and can detect the onset of disease. In this paper, we propose two methods to improve the signal to noise ratio (SNR) of the sensor, which is one of the main characteristics of the FO-LSPR sensor. The first method is to increase the intensity of the sensor by increasing the size of gold nanoparticle (Au NP) formed on the optical fiber surface by Au capping method. The second method is to form a structure that reduces the reflection by increasing the roughness of the surface by etching the surface of the optical fiber using the Au NP formed on the surface of the optical fiber as a mask. Increasing the roughness of the optical fiber surface can reduce the background signal of the sensor. The two methods mentioned above can increase the SNR of the sensor. When the SNR of the sensor is increased, the efficiency of the sensor is improved.