Here we propose a new design of an on-chip micro-flow cytometry based on photonic crystals. When individual cells flow tangential to the crystal surface, the transmission of the light through the photonic crystal changes depending on the presence or absence of the cells and their size and shape. This system was modeled using OptiFDTD, where transmission spectra were extracted. Initially, the potential for cell counting has been demonstrated. Then, for cells with differing shape a direct relation between signal distribution and cell shape has been found.

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a b s t r a c t Administering a wrong drug or a wrong dose can be extremely dangerous and can result in severe adverse effects or even the death of a patient. With human errors being possible, automatic real time identification of a drug and its concentration using technology is a viable option to decrease the chance of incorrect drug administration. As a step toward this goal, we propose a new optical fiber based spectroscopic system that has built-in filtration capabilities and thus can work in real time near patient without additional sample pre-processing. It is designed as a point probe consisting of an optical fiber with a miniature filtering reflector integrated on the interface. In the future it can be inserted into a bag for intravenous therapy (IV therapy) or in a syringe to measure the spectrum of the fluid and to confirm its properties. Additionally, use of microfluidic filtration allows to remove microscopic particles from the sample and thus decreases the noise and increases the sensitivity of spectroscopic measurement. In this study, an optofluidic system was fabricated, and filtration capabilities and measurement of cobalamin (vitamin B 12 ) concentration have been demonstrated. Ó 2014 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/3.0/).

Photonic crystal flow cytometry is a very attractive platform due to its great sensitivity in combination with a very compact design. Previous studies have demonstrated the possibility to use spectral processing for the measurement of a wide range of parameters, from simple object counting to independent analysis of the buffer solution and immersed microscale objects. Here we propose to go to the next level and simultaneously determine the shape and the refractive index of the cells.