In a significant stride towards enhancing sensor technology, researchers have developed a novel surface plasmon interferometric sensor that promises higher sensitivity and multiplexing capabilities. The study, led by Marcos Valero from the School of Engineering and Sciences at Tecnológico de Monterrey and the School of Electrical Engineering and Computer Science at the University of Ottawa, opens new avenues for advanced sensing applications, particularly in the energy sector.
Surface plasmon interferometers, known for their phase-based sensing, offer a leap in sensitivity compared to traditional resonant or attenuation-based plasmonic sensors. Valero and his team have harnessed this advantage by fabricating sensors using multimode nanoslits as combiners. “The phase difference in the surface plasmon waves incident on the nanoslit determines the resonant mode excited therein, and the radiation pattern that emerges therefrom,” explains Valero. This innovative approach allows for precise and sensitive detection of changes in the surrounding environment.
The device construction is a marvel of miniaturization and integration. It combines on-chip grating couplers, gold sensing and reference surfaces, transparent claddings, sealed microfluidic channels, and a nanoslit in the gold film. The structure can be arrayed with individual microfluidic channels, enabling multiplexing—a feature crucial for simultaneous detection of multiple analytes. The fabrication process involves a complex integration of techniques such as photolithography, electron beam lithography, focused ion beam milling, plasma etching, wafer bonding, and dicing, all requiring precise overlay and alignment.
One of the most compelling aspects of this research is its potential impact on the energy sector. Advanced sensing technologies are vital for monitoring and optimizing energy production and distribution processes. The high sensitivity and multiplexing capabilities of these sensors could revolutionize real-time monitoring of oil and gas pipelines, detecting leaks or contaminants with unprecedented accuracy. “This technology could significantly enhance safety and efficiency in the energy industry,” Valero notes, highlighting the practical implications of their work.
The researchers also developed a test jig to facilitate the mounting and optical interrogation of the chips, ensuring seamless integration into existing systems. The operation of the devices was demonstrated through refractometric (bulk) sensing experiments, showcasing their effectiveness in real-world applications.
The study, published in the Journal of Physics Photonics (translated to English as “Journal of Physics: Photonics”), represents a significant advancement in the field of nanofabrication and sensor technology. The fabrication flow presented in the research can be scaled to mass-manufacturing, paving the way for widespread adoption of these innovative sensors.
As the energy sector continues to evolve, the demand for advanced sensing technologies will only grow. This research not only meets this demand but also sets a new standard for sensitivity and multiplexing capabilities. The implications of this work extend beyond the energy sector, with potential applications in environmental monitoring, healthcare, and industrial processes. The future of sensing technology looks brighter with these groundbreaking developments.