Unparalleled Sensitivity Unlocking High Volume Demand of Photonic Biosensors for Point-of-Care (POC) Diagnostics

Project Overview:

The project focuses on advancing a photonic biosensor platform for point-of-care (POC) in vitro diagnostic applications. The initiative aims to transition an existing laboratory-scale prototype into a robust, scalable system suitable for routine clinical and industrial use. The work builds on prior demonstrations of highly sensitive biomarker detection using silicon nitride (SiN) photonic chips combined with microfluidics and surface functionalisation technologies.

Project Goal:

The primary goal of the project is to develop an integrated diagnostic platform that achieves high analytical sensitivity while remaining compatible with cost-effective, high-volume production. The project aims to:

• Improve sensor performance for both protein and molecular biomarker detection.
• Enable reproducible operation in clinical and field environments.
• Prepare the underlying photonic and microfluidic components for industrial-scale manufacturing.

The intended outcome is a platform capable of multiplex and multi-modal detection with performance parameters aligned with established in vitro diagnostic (IVD) requirements.

Background and Context

Conventional POC diagnostic systems often face limitations related to sensitivity, cost, and operational complexity. At the same time, healthcare settings increasingly require diagnostic tools that provide rapid and reliable results without dependence on central laboratory infrastructure. Photonic biosensing offers a potential pathway to improved performance due to its ability to measure biomolecular interactions through changes in optical signals, enabling reduced detection limits and support for multiplexed assays.

The project’s foundation is a SiN photonic chip functionalised with proprietary nanocoatings and integrated into a disposable microfluidic cartridge. A compact readout unit provides optical interrogation of the chip. Previous studies have shown that this architecture can achieve detection limits in the low-picogram-per-millilitre range for several biomarker classes.

Scope of Work

The project is divided into two main programmes: Application Technology Development and Industrialisation & Scale-Up. Each addresses specific technical and manufacturing challenges required to move the platform toward practical deployment.

1. Application Technology Programme

This programme focuses on improving the analytical performance of the biosensor platform. The work includes:

• Sensor Chip Design Enhancements
  • Development of new waveguide geometries and extended sensing areas.
  • Reduction of chip footprint to support lower-cost cartridge production.
• Optical Signal Amplification Methods
  • Evaluation and optimisation of amplification agents.
  • Improvement of conjugation strategies to enhance detection at low analyte concentrations.
• Advanced Mixing Strategies
  • Implementation of microfluidic structures and acoustic mixing to improve transport of analytes to the sensor surface.
  • Investigation of diffusion-limited behaviour and methods to mitigate it.
• Reduction of Signal Drift and Noise
  • Refinement of electronics, thermal management, and data-processing approaches.
  • Exploration of algorithmic techniques, including AI-based methods, for stable signal extraction.
• Integration and Validation
  • Assembly of improved subsystems into a unified platform.
  • Validation through assays based on clinically relevant biomarker concentrations.

2. Industrialisation and Scale-Up Programme

This programme addresses manufacturability, quality control, and readiness for IVD-level production volumes. Key elements include:

• Transition to Grating-Coupled Chip Designs
  • Replacement of edge-coupling with grating coupling to increase alignment robustness.
  • Suitability for automated packaging and high-volume assembly.
• Wafer-Scale Production Enhancements
  • Scaling from 4-inch to 8-inch wafers to reduce unit cost.
  • Alignment of process flows with standard industrial photonics fabrication practices.
• Readout Unit Adaptation
  • Design of a measurement module compatible with grating-coupled chips.
  • Development of optical and mechanical interfaces for consistent coupling.
• Wafer- and Module-Level Optical Quality Control
  • Introduction of inspection tools and procedures suitable for 850 nm devices.
  • Establishment of QC criteria that support regulatory requirements for diagnostic devices.

Collaboration Structure

The project involves contributions from industrial, academic, and technology-development partners. Activities span specialised areas such as silicon nitride photonic fabrication, microfluidics manufacturing, optical assembly, acoustic mixing research, system integration, software development, and quality-control methodology. Together, the partners constitute a value chain capable of supporting prototype development and pilot-scale production.

Expected Outcome

Upon completion, the project is expected to deliver:

• A validated POC biosensing platform demonstrating sensitivity and reproducibility compatible with diagnostic workflows.
• A set of manufacturing processes for photonic chips, microfluidic cartridges, and readout modules suitable for industrial scaling.
• A coordinated ecosystem capable of supporting future commercialisation and clinical evaluation phases.