Surface Plasmon Array Sensor (SPlAS)

Background

Optical sensors based on plasmonic interactions and fluorescence have been used in sensing applications. However, these methods typically involve expensive imaging spectrometers and light sources to measure spectral changes.

Description of the invention

Based on a unique two-dimensional metallic nanopatch design, University of Waterloo researchers have developed a substrate which reflects vivid colours. Surface Plasmon resonance can be induced on the nano-patch array design by simply using an off the shelf white light source, such as LED. The surface plasmon resonance effect gives rise to a unique visible spectrum signature that can be used to sense changes in colour of the nano-patch substrate. Thus, by simply measuring the change of colour, the refractive index changes in surrounding region can be ascertained. A refractive index sensor with a resolution better than 3x10^-6 has already been demonstrated allowing the technology to be used in multiple fields. The colour change can be detected by the naked eye, a low cost imaging camera, or by using cheap bright-field microscopy depending on sensitivity requirements. The same chip enhances Raman signal of detectants by a factor of 10 million which makes the chip suitable for specificity tests. Further improvements on the invention are underway and integration with micro-fluidic channels to create a lab-on-a-chip device is also being investigated. The sensor uses low cost glass material, low cost light source, and a simple imaging camera which potentially allows for inexpensive optical sensors.

Advantages

The sensor has the resolution of photonic integrated circuit based sensors at a fraction of the cost. The simplicity of detection allows for it to be used by virtually anyone with no technical training. The other advantage is the small and compact size of the final product, which allows for mobile sensing. The sensor allows label free detection with rapid turnaround time and can be designed as large two-dimensional assays.

Potential applications