A spiropyran with enhanced fluorescence

10 November 2017:

A new rationally designed, photostable, red-emitting calcium sensor with enhanced fluorescence intensity has been presented by CNBP researchers in a paper published in the journal ‘Tetrahedron’. Lead author on the paper is CNBP’s Georgina Sylvia (pictured – University of Adelaide).

Journal: Tetrahedron.

Publication titleA spiropyran with enhanced fluorescence: A bright, photostable and red-emitting calcium sensor.

Authors: Georgina M. Sylvia, Sabrina Heng, Akash Bachhuka, Heike Ebendorff-Heidepriem,
Andrew D. Abell.

A rationally designed, pyrene-spiropyran hybrid Ca2+ sensor (Py-1) with enhanced fluorescence intensity compared to a standalone spiropyran analogue is presented. Importantly, Py-1 retains the characteristic red emission profile of the spiropyran, while fibre-based photostability studies show the sensor is stable after multiple cycles of photoswitching, without any sign of photodegradation. Such properties are of real advantage for cell-based sensing applications. An interesting observation is that, Py-1 presents with two excitation options; direct green excitation (532 nm) of the photoswitch for a red emission, and UV excitation (344 nm) of the component pyrene, which gives rise to distinct blue and red emissions. This proof-of-concept hybrid sensing system presents as a more general approach to brighter spiropyran-based sensors.