Ultrasensitive Surface Plasmon Resonance Biosensor Using Blue Phosphorus-Graphene Architecture.

Keyi Li,Yufeng Yuan,Lintong Li,Yingxin Zhou,Junle Qu,Xiao Peng,Nanlin Xu,Jun Song

doi:10.3390/s20113326

Abstract

This study theoretically proposed a novel surface plasmon resonance biosensor by incorporating emerging two dimensional material blue phosphorus and graphene layers with plasmonic gold film. The excellent performances employed for biosensing can be realized by accurately tuning the thickness of gold film and the number of blue phosphorus interlayer. Our proposed plasmonic biosensor architecture designed by phase modulation is much superior to angular modulation, providing 4 orders of magnitude sensitivity enhancement. In addition, the optimized stacked configuration is 42 nm Au film/2-layer blue phosphorus /4-layer graphene, which can produce the sharpest differential phase of 176.7661 degrees and darkest minimum reflectivity as low as 5.3787 × 10−6. For a tiny variation in local refractive index of 0.0012 RIU (RIU, refractive index unit) due to the binding interactions of aromatic biomolecules, our proposed biosensor can provide an ultrahigh detection sensitivity up to 1.4731 × 105 °/RIU, highly promising for performing ultrasensitive biosensing application.

Highlights

Since the discovery of black phosphorus (BP), another two dimensional (2D) allotrope of phosphorus named blue phosphorus (BlueP) has been predicted theoretically and successfully engineered in laboratory [1,2,3,4,5]
We proposed a novel surface plasmon resonance (SPR) biosensor with ultrahigh detection sensitivity by integrating emerging blue phosphorus and graphene nanosheets onto plasmonic gold film
Both light absorption and energy loss in our proposed configuration can be maintained in a balance state by tuning the thickness of the gold film and the number of blue phosphorus interlayers

Summary

Introduction

Since the discovery of black phosphorus (BP), another two dimensional (2D) allotrope of phosphorus named blue phosphorus (BlueP) has been predicted theoretically and successfully engineered in laboratory [1,2,3,4,5]. Blue phosphorus has shown high stability with the previously reported black phosphorus [2]. Theoretical studies have shown that blue phosphorus has a tunable band gap ranging from 2 eV to 1.2 eV from monolayer to bulk [1], making it a promising candidate for designing novel optoelectronic devices such as gas sensors [6] quantum spin Hall insulators [7] and Dirac cones [8]. Compared with a single 2D material, the heterostructures can generate more novel electronic and optical features such as phonon frequency, binding energy, and carrier mobility [11]. The optical and electronic features of 2D heterostructures are highly dependent on both the number of

Methods

Discussion

Conclusion