Illinois Researchers Develop Nanoplasmonic Spectroscopy Sensing Device
20 February 2013
A famous Roman cup made of dichroic glass has inspired University of Illinois at Urbana-Champaign scientists to develop a nanoplasmonic spectroscopy sensing device that is capable, for the first time, of achieving colorimetric sensing.
The new sensor can be used for chemical and biomolecular imaging and can be integrated with portable microfluidics devices for lab-on-chip applications. Because of its low cost, simple design and high sensitivity, the device is expected to have wide applications in chemical, DNA and protein analysis.
The sensor was developed on the basis of the optical characteristics of the Lycurgus Cup, made by the Romans in 400 AD. The cup, which shows different colors depending on what side it is lit from, has inspired all nanoplasmonics research that is being carried out today.
Logan Liu, an assistant professor of electrical and computer engineering and of bioengineering, and his team achieved the dichroic effect in the new device by including very small proportions of finely ground silver and gold dust in the glass. Their device consists of some one billion nanocups in an array with a subwavelength opening and decorated with metal nanoparticles on side walls, exhibiting similar properties and shape to the Lycurgus Cup on display in the British Museum. The researchers were very excited about the extraordinary characteristics of the material, which has 100 times higher sensitivity than any other reported nanoplasmonic device.
The proposed structure relies on localized surface plasmon mediated enhanced optical transmission (EOT) which provides greater controllability over tuning the resonance wavelengths of the sensor.