Balanced plasmonic-augmented silicon photonic interferometric sensor for biosensing applications

Optics Express, vol. 33, pp. 23110

Abstract

We demonstrate a self-referenced plasmonic augmented photonic Mach-Zehnder interferometer (MZI) for biosensing applications, incorporating a 70 µm long aluminum plasmonic waveguide in both arms of a silicon nitride (Si3N4) MZI. Experimental results matched well with numerical simulations, showing extinction ratio (ER) values that exceed 55 dB and bulk sensitivity of 2322 nm/RIU. Wavelength stability measurements revealed 5×10−3 nm thermal dependance for an ambient temperature fluctuation of 1-degree Celsius which is 50 times better than a conventional hybrid plasmo-photonic asymmetric MZI (aMZI) configuration, highlighting the robustness of the proposed balanced sensor scheme to ambient temperature fluctuations. Moreover, the experimental results show that the proposed sensor has a limit of detection up to 2.6 ×10−6 RIU. Surface sensitivity of the proposed sensing transducer was evaluated through a C-reactive protein (CRP) surface saturation measurements and found equal to 10.45 nm/RIU for protein binding. Our validated simulation model was then benchmarked against a diverse set of target bio-analytes (proteins, viruses, bacteria, fungi) with surface sensitivity values reaching up to 2306 nm/RIU, indicating the sensor's heterogeneous detection capabilities. The presented self-referencing sensor configuration offers a cost-effective yet scalable and highly sensitive approach for multiplexed on-chip detection of diverse target analytes.

Authors 10

1. Mahmoud A. Elrabiaay
   Affiliation as printed

   bialoom Ltd

2. Christia Eleftheriou
   Affiliation as printed

   bialoom Ltd

3. George Tsekenis
   Affiliation as printed

   bialoom Ltd

4. Omkar Bhalerao Aachen

   RWTH Aachen University

   Affiliation as printed

   Advanced Microelectronic Center Aachen

   RWTH Aachen University

5. Stephan Suckow
   Affiliation as printed

   Advanced Microelectronic Center Aachen

6. Max C. Lemme Aachen

   RWTH Aachen University

   Affiliation as printed

   Advanced Microelectronic Center Aachen

   RWTH Aachen University

7. Pratyusha Das

   Université Bourgogne Europe

   Affiliation as printed

   Université Bourgogne Europe

8. Laurent Markey

   Université Bourgogne Europe

   Affiliation as printed

   Université Bourgogne Europe

9. Athanasios Manolis
   Affiliation as printed

   bialoom Ltd

10. D. Tsiokos
    Affiliation as printed

    bialoom Ltd