Combining optical trapping in a microfluidic channel with simultaneous micro-Raman spectroscopy and motion detection

Lawton, P.F.; Saunter, C.D.; Girkin, J.M.

Abstract

Since their invention by Ashkin optical tweezers have demonstrated their ability and versatility as a non-invasive tool for micromanipulation. One of the most useful additions to the basic optical tweezers system is micro-Raman spectroscopy, which permits highly sensitive analysis of single cells or particles. We report on the development of a dual laser system combining two spatial light modulators to holographically manipulate multiple traps (at 1064nm) whilst undertaking Raman spectroscopy using a 532nm laser. We can thus simultaneously trap multiple particles and record their Raman spectra, without perturbing the trapping system. The dual beam system is built around micro-fluidic channels where crystallisation of calcium carbonate occurs on polymethylmethacrylate (PMMA) beads. The setup is designed to simulate at a microscopic level the reactions that occur on items in a dishwasher, where permanent filming of calcium carbonate on drinking glasses is a problem. Our system allows us to monitor crystal growth on trapped particles in which the Raman spectrum and changes in movement of the bead are recorded. Due to the expected low level of crystallisation on the bead surfaces this allows us to obtain results quickly and with high sensitivity. The long term goal is to study the development of filming on samples in-situ with the microfluidic system acting as a model dishwasher.

Citation

Lawton, P., Saunter, C., & Girkin, J. (2014, March). Combining optical trapping in a microfluidic channel with simultaneous micro-Raman spectroscopy and motion detection. Presented at Microfluidics, BioMEMS, and Medical Microsystems XII, San Francisco, California, United States

• Presentation Conference Type: Conference Paper (published)
• Conference Name: Microfluidics, BioMEMS, and Medical Microsystems XII
• Acceptance Date: Mar 2, 2014
• Publication Date: Mar 1, 2014
• Deposit Date: Nov 18, 2015
• Publicly Available Date: Nov 24, 2015
• Volume: 8976
• Series Number: 8976
• Series ISSN: 0277-786X,1996-756X
• Book Title: Proceedings of SPIE.
• DOI: https://doi.org/10.1117/12.2037022
• Keywords: Optical tweezers, Raman spectroscopy, Crystallization, Motion detection.
• Public URL: https://durham-repository.worktribe.com/output/1153035