Miniature Photonic Technologies for Biomedical Applications

Background: There is a continuously increasing trend in finding miniature solutions that can be portable and cost effective aligned with the fact that miniature optoelectronic components become available at low cost such as cameras and spectrometers. Such low-cost, portable sensing and diagnostic systems are crucial in for point of care (POC), in resource limited and remote regions of the world for medical diagnosis, environmental monitoring and nutrition examination. Popular sensing technologies are based on ELISA, polymerase chain reaction (PCR), mass spectroscopy (MS), surface plasmon resonance (SPR), electrochemical immunoassays, fluorescence microscopy and others. These existing approaches have achieved high sensitivities, however they often rely on bulky instrumentation and costly chemical procedures, requiring well-trained operators and advanced laboratory infrastructure.

Methods and Results: During the last few years we have been developing a number of technologies that help in building such miniature modules for sensing and diagnostics. Our research activities involve three interrelated activities to serve this purpose: (i) Liquid crystal active devices developed and used in spectral and polarimetric imaging modules, extended depth of field camera and white light ellipsometric camera; (ii) Highly sensitive plasmonic biosensing substrates that can be read with miniature modules such as SPR module of 5cm height, self-referenced nanograting structure, surface enhanced Raman spectroscopy (SERS) and fluorescence (SEF) substrates; and (iii) Fast parallel phase shift detection based methods for quantitative phase imaging, focus tracking, vibration measurement, ellipsometry and quantitative phase imaging.

Conclusion: A short review will be given with some demonstrated applications in biosensing and diagnostics.