Health

Prof. David Marpaung’s team focuses on improving sensing unit performance. Using passive Al₂O₃ microring resonators, they have detected rhS100A4 proteins in undiluted urine at clinically relevant levels (0.3 nM) with an impressive limit of detection (LOD) of ~10⁻⁶ RIU. By leveraging modular microring laser cavity sensors, they have pushed the LOD even lower to 6.0 × 10⁻⁸ RIU. Athermal design and self-reference grating structures further minimise temperature sensitivity, ensuring stable results.

The team is also developing biosensors capable of detecting multiple biomarkers simultaneously in blood or urine. This approach enables a full diagnostic test within minutes, offering instant insights into multiple health indicators.

Key challenges

• Auto-Align Setups for Optical Biosensing Chips: Creating user-friendly systems that combine optical chip design, microfluidics, temperature control, and active alignment algorithms. The first setup is accessible to non-optics students after a brief introduction, a major step toward practical medical applications.
• Highly Multiplexed Optical Biosensors: New analysis algorithms allow over eight channels on a single detector, enabling the simultaneous detection of more than 8×16 analytes.

Developing next-generation biosensors requires expertise from multiple fields:

• Mechanical engineering for system alignment and thermal management.
• Electrical engineering for readout module development.
• Software engineering for signal processing.
• Chemistry for surface modification and antibody/capture probe development.
• Photonic and microfabrication engineers for chip design and manufacturing.
• Microfluidic engineers for precise analyte delivery.

By merging these disciplines, the team is pushing the boundaries of integrated photonic biosensing.