Sensitivity Improvement of Surface Plasmon Resonance Biosensors with GeS-Metal Layers

Abstract

Surface plasmon resonance (SPR) biosensors, with germanium sulfide (GeS) as a sensitive medium and Al/Ag/Au as the metal layers, are reported as we aim to improve the sensitivities of the biosensors. The sensitivities in conventional SPR biosensors, consisting of only metal Al, Ag, and Au layers, are 111°/RIU, 117°/RIU, 139°/RIU, respectively. Additionally, these sensitivities of the SPR biosensors based on the GeS-Al, GeS-Ag, and GeS-Au layers have an obvious improvement, resultant of 320°/RIU, 295°/RIU, and 260°/RIU, respectively. We also discuss the changing sensing medium GeS thickness using layer number to describe the scenario which brought about the diversification on the figure of merit (FOM) and optical absorption (OA) performance of the biosensors. These biosensors show obvious improvement of sensitivity and have strong SPR excitation to analytes; we believe that these kind biosensors could find potential applications in biological detection, chemical examination, and medical diagnosis.

Advances in Plasmonic Photonic Crystal Fiber Biosensors: Exploring Innovative Materials for Bioimaging and Environmental Monitoring

“…demonstrated that the GeS monolayer possesses significantly higher carrier mobility (3680 cm 2 V −1 ) than MoS 2 monolayers [127] . Sensor studies indicate the highest sensitivities for GeS−Al, GeS−Ag, and GeS−Au films at 320 deg/RIU, 295 deg/RIU, and 260 deg/RIU, respectively, surpassing conventional SPR sensors based on Al/Ag/Au films at 111 deg/RIU, 117 deg/RIU, and 139 deg/RIU, respectively [128] . A study executed by Zhao [34] illustrates a substantial advancement in sensitivity for RI detection, achieving an optimized sensitivity of 3581.2 nm / RIU and a figure of merit of 14.37 RIU −1 .…”

“…[127] Sensor studies indicate the highest sensitivities for GeSÀ Al, GeSÀ Ag, and GeSÀ Au films at 320 deg/ RIU, 295 deg/RIU, and 260 deg/RIU, respectively, surpassing conventional SPR sensors based on Al/Ag/Au films at 111 deg/ RIU, 117 deg/RIU, and 139 deg/RIU, respectively. [128] A study executed by Zhao [34] illustrates a substantial advancement in sensitivity for RI detection, achieving an optimized sensitivity of 3581.2 nm/RIU and a figure of merit of 14.37 RIU À 1 . This improvement, nearly 80 % greater than conventional SPR sensors, results from covering the gold film with stable and cost-effective Germanium selenide (GeSe) nanosheets.…”

A performance comparison of heterostructure surface plasmon resonance biosensor for the diagnosis of novel coronavirus SARS-CoV-2

“…Similarly, At a wavelength (λ), the RI of plasmonic metal (Ag or Au) can be computed from the Drude–Lorentz model (Rahman et al 2020 , 2021 ; Panda and Pukhrambam 2021 ; Wu et al 2017 ; Jia et al 2019 , 2022 ): …”

A Performance Comparison of Heterostructure Surface Plasmon Resonance Biosensor for the Diagnosis of Novel Coronavirus SARS-CoV-2

“…1. At a particular incident wavelength (𝜆) of 632.8 nm on the prism, the RI of the CaF2 prism and TiO2 adhesion layer can be calculated through the ensuing (1) and (2) as follows [52], [58]: Similarly, At a wavelength (𝜆), the RI of plasmonic metal (Ag or Au) can be computed from the Drude-Lorentz model [41], [52], [56], [59]- [61]:…”