Fiber-optic detection of pH for in vivo analysis of sub-microliter natural samples

Sponsor: Ministry of Education, Youth and Sports of the Czech Republic

Principal investigator: Ivan Kašík, Ph.D.

From: 2006-03-01

To: 2011-12-31

Miniaturization and application of advanced engineering principles on natural objects belong to the hottest trends of modern science and technology. Understanding of processes, their dynamics and gradients in microscopic samples of plant or animal origin push the limits of fundamental knowledge of the nature further. The research of fiber-optic sensors is a proper answer to today´s calls. Therefore, special attention has been focused on local detection of pH by the use of fiber-optic probes which are only several micrometers in size. The elaborated method, which is based on ratiometric fluorescence principle, make it possible for in vivo determination of pH with the resolution of ~0.1 pH unit during several seconds within a biological range of pH from 5.5 to 7.5. It allows minimum invasive monitoring of natural living samples (droplets, tissues, embryos, body liquids) of small volumes with the minimum resolution of individual cells. A laboratory setup was constructed the method was tested on a process which focused on the characterization of microscopic hair roots of Arabidopsis thaliana. Unique results important for plant nutrition and agriculture production were achieved by joining effort of researchers from the Institute of Photonics and Electronics ASCR and the Institute of Experimental Botany in outstanding collaboration with Safibra Ltd.

References:

1. Kašík, I. - Mrázek, J. - Martan, T. - Pospíšilová, M. - Podrazký, O. - Matějec, V. - Hoyerová, K. – Kamínek, M.: Fiber-optic pH detection in small volumes of biosamples. Anal. Bioanal. Chem. Roč. 398 (2010), 1883-1889.
2. I. Kašík, O. Podrazký, J. Mrázek, T. Martan, V. Matějec, K. Hoyerová, M. Kamínek: „In vivo optical detection of pH in microscopic tissue samples of Arabidopsis thaliana“, Materials Science & Engineering C 33 (2013), 4809-4815
3. I. Kašík, T. Martan, O. Podrazký, J. Mrázek, M. Pospíšilová, V. Matějec, „Local real-tme detection of pH using fibre tapers“, Proc. SPIE 7356 - Optical Sensors 2009, Prague, 20-22 April 2009, 73561U-1 – 73561U-6.
4. T. Martan, J. Kaňka, I. Kašík, V. Matějec: „Tapered optical fibres for sensing“, Proc. SPIE 7138, Photonics Prague 2008, Prague, August 2008, 71380Z-1 – 71380Z-6.
5. O. Podrazky, J. Mrazek, M. Seidl, I. Kasik, P. Tobiska, V. Matejec, T. Martan, J. Aubrecht: “Optical principle of pH measurement for detection of auxin flow through cellular membrane“, Proc. SPIE 6585 - Optical Sensing Technology and Applications, Prague, April 2007, 65850Y.1-6580Y.7