A Fabry-P\xe9rot cavity coupled surface plasmon photodiode for electrical biomolecular sensing

Giles Allison,Amrita Kumar Sana,Hiroaki Misawa,Yuta Ogawa,Hidemi Kato,Kosei Ueno,Hironori Suzuki,Koki Hayashi

doi:10.1038/s41467-021-26652-7

Abstract

Surface plasmon resonance is a well-established technology for real-time highly sensitive label-free detection and measurement of binding kinetics between biological samples. A common drawback, however, of surface plasmon resonance detection is the necessity for far field angular resolved measurement of specular reflection, which increases the size as well as requiring precise calibration of the optical apparatus. Here we present an alternative optoelectronic approach in which the plasmonic sensor is integrated within a photovoltaic cell. Incident light generates an electronic signal that is sensitive to the refractive index of a solution via interaction with the plasmon. The photogenerated current is enhanced due to the coupling of the plasmon mode with Fabry-Pérot modes in the absorbing layer of the photovoltaic cell. The near field electrical detection of surface plasmon resonance we demonstrate will enable a next generation of cheap, compact and high throughput biosensors.

Highlights

Surface plasmon resonance is a well-established technology for real-time highly sensitive label-free detection and measurement of binding kinetics between biological samples
The recent pandemic caused by the novel coronavirus (SARS-CoV-2) has served as one example to heighten the value of technologies able to rapidly test for the presence of antibodies and antigens[10,11]
The device is mounted onto a prism in the Kretschmann geometry[21] (Fig. 1a) that is mounted onto a rotating stage

Summary

Introduction

Surface plasmon resonance is a well-established technology for real-time highly sensitive label-free detection and measurement of binding kinetics between biological samples. We confirm the mechanism through simulations of the electric field and show experimentally the electric detection of the plasmon mode and use this method to detect changes in refractive index (RI) and protein–protein interactions—in this case, antigen–antibody interaction of the SARS-CoV-2 nucleocapsid protein. The generated photocurrent depends on the wavelength of light, thickness of silicon layer, and angle of illumination.

Results

Conclusion