AI-integrated SPRi with adaptive microwell-array recognition for high-throughput parallel readout

Sensors and Actuators Reports, pp. 100538

Abstract

Multiplexed biosensing is essential for clinical diagnostics and increasingly being enabled by Surface Plasmon Resonance Imaging (SPRi), a label-free detection technique allowing precise and real-time detection of multiple analytes. Although, current SPRi platforms remain constrained by optical artifacts, manual image analysis, and high operational costs. This work presents an AI-integrated SPRi (AI-SPRi) platform featuring microwell-arrays with diameters 200 to 1000 µm, to support future multiplexed operation on chip across a wide refractive-index (RI) range. AI-SPRi performs high-resolution SPRi with large field-of-view (FoV) using lithographically fabricated sensor chips (∼5% variation) and augments SAM2-based integration of a SPR data pipeline, for the first time in biosensors context. The pipeline achieves 83.9% microwell-detection recall, a 32% improvement over the base model, with detection of 200 µm wells (∼70% of the array), rising from 41% to 80%. Here, a two-step algorithm corrects geometric (perspective) distortion, complemented by flat-field illumination correction, quantitative signal extraction, and post-processing, reducing per-chip analysis of all 156 sensing spots to few minutes. On the monotonic resonance flank (1.333–1.345 RIU at 57.3°), pipeline processing cuts intra-region noise by 38–53% and improves limit-of-detection (LoD) from 3.8, 6.3, and 11.0 mRIU to 2.2, 4.1, and 10.0 mRIU for 1000, 380, and 200 µm diameter wells, respectively. Gold-specific adsorption of a nanobody-peptide conjugate confirmed that the standardization of signal acquisition pipeline extends to molecular-binding studies, with the inter-size readout coefficient of variation (CV) falling from 16.4% to 5.9%, establishing a proof of concept of a high-throughput AI-SPRi for the realization of future multiplexed bioassays.

Authors 16

1. Ahmed Ben Romdhane Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

2. Michael Scheiterer Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

3. Daniele Storelli Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

4. Divagar Murugan Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

5. Eashika Ghosh Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

6. Peiyuan Gong Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

7. Hocine Bahri Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

8. Hesam Amiri Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

9. Dibyendu Khan Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

10. Franziska Hesse Aachen Institute of Materials in Electrical Engineering 1

    RWTH Aachen University

    Affiliation as printed

    Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

11. Aidin Nikookhesal Aachen Institute of Materials in Electrical Engineering 1

    RWTH Aachen University

    Affiliation as printed

    Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

12. Chishu Homma Aachen Institute of Materials in Electrical Engineering 1

    RWTH Aachen University

    Affiliation as printed

    Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

13. Priyanka Thawany Aachen Institute of Materials in Electrical Engineering 1

    RWTH Aachen University

    Affiliation as printed

    Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

14. Johannes Stegmaier Aachen Institute of Imaging & Computer Vision

    RWTH Aachen University

    Affiliation as printed

    Institute of Imaging and Computer Vision, RWTH Aachen University, Aachen, Germany

15. Sven Ingebrandt Aachen Institute of Materials in Electrical Engineering 1

    RWTH Aachen University

    Affiliation as printed

    Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany

16. Vivek Pachauri corresponding Aachen Institute of Materials in Electrical Engineering 1

    RWTH Aachen University

    Affiliation as printed

    Institute of Materials in Electrical Engineering 1, RWTH Aachen University, Sommerfeldstrasse 18a, 52074 Aachen, Germany