Optical Coherence Tomography (OCT) Systems
The biophotonics group has a 1310 nm swept-source polarisation-sensitive optical coherence tomography system. The setup is optimised for deep tissue imaging, allowing both structural and birefringent properties from biological tissue to be extracted. The system has been used for a range of projects including early diagnosis of cartilage degeneration, prediction of red meat quality in real-time, and forensic assessment of artwork.
The imaging head of the system has a large working distance (100mm) and can take 3D volumes with dimensions of approximately 20 mm x 20 mm x 5mm. We are working toward mobilising the system making it completely portable and able to meet the needs of those who would like to explore the potential of OCT for their application.
We also have a spectral domain optical coherence tomography system (720-980nm). This system is ideal for high-resolution, non-invasive, non-contact imaging of samples with high content of water like an eye, different plants or vascular structures.
We use this system mostly for the studies on eyes to look for early signs of different diseases, but we also imaged: blueberries to test for the best storage conditions, grapes to see changes with calcium treatment and intestinal villi (ex-vivo) to find indicators of diseases.
We can obtain 3D images (10mmx10mmx1.5mm) with the resolution of 3.6µm in depth, 24µm laterally and imaging range of 1.5mm in depth. Also, we can observe the temporal evolution of a certain part of our image, what we use to obtain the information about the stiffness of our samples, this method however is used mostly for homogenous samples.
Microfluidic Flow Cytometry System
We have a microfluidic flow cytometry system that is optimised for food safety applications to detect and characterise single baterial cells extracted from food swabs. In this system, excitation is provided by a 473 nm laser source and a Ocean Optics QE Pro High-Sensitivity Fiber Optic Spectrometer which delivers a dynamic typical range of 85,000:1 and a signal-to-noise ratio of 1000:1 (at full signal) is used for the detection of fluorescent signal. The system also has a pressure driven flow pump (Elveflow OB1-MK3) which allows good flow stability and superior flow control even at low flow rates. Each channel of the OB1 MK3 pressure controller is connected to a flow sensor which allows us to monitor and control flow rates in our microfluidic setup while keeping stability and responsiveness of pressure driven flows.
Centrifugal Microfluidics System
We have a centrifuge that is used for centrifugal microfluidics experiments for food safety applications.