In Vitro and in Cellulo Sensing of Transition Metals Using Time-Resolved Fluorescence Spectroscopy and Microscopy

Pal, Robert; Barker, Abigail C.J.; Hummel, Daniel; Pålsson, Lars-Olof

Abstract

In this work we demonstrate that time domain techniques can be used successfully to monitor realtively weak modulations of the fluorescence in sensing applications. The metal sensing complex Newport Green DCF™ can detect selected transition metals in vivo as well as in vitro. Incremental addition of Ni and/or Zn (in vitro) lead to a substantial reduction in the yield of the fast component in a bi-exponential fluorescence decay (τ1 = 150–250 ps) from 60% to 30–35%. This is rationalised as an inhibition of intra-molecular electron transfer in the NPG sensing complex due to metal complexation. In order to explore this effect in cellulo, NIH 3 T3 mouse skin fibroplast cells were pre-incubated with set levels of Ni and Zn, at a constant concentration of NPG. The fluorescence modulation in cellullo was subsequently studied employing both time-resolved fluorescence microscopy and confocal fluorescence microscopy. In correlation with the in vitro observations, similar effects were observed on the fluorescence decay in cellulo.

Citation

Pal, R., Barker, A. C., Hummel, D., & Pålsson, L. (2019). In Vitro and in Cellulo Sensing of Transition Metals Using Time-Resolved Fluorescence Spectroscopy and Microscopy. Journal of Fluorescence, 29(1), 255-263. https://doi.org/10.1007/s10895-018-2335-z

• Journal Article Type: Article
• Acceptance Date: Dec 11, 2018
• Online Publication Date: Dec 26, 2018
• Publication Date: Jan 31, 2019
• Deposit Date: Jan 4, 2019
• Publicly Available Date: Jan 4, 2019
• Journal: Journal of Fluorescence
• Print ISSN: 1053-0509
• Electronic ISSN: 1573-4994
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 29
• Issue: 1
• Pages: 255-263
• DOI: https://doi.org/10.1007/s10895-018-2335-z
• Public URL: https://durham-repository.worktribe.com/output/1340583