SBIC ECR Symposium & Poster Presentation 21st International Conference on Biological Inorganic Chemistry 2025

Glowing insights: luminescent lanthanide fibre optic sensors for oxidative stress detection (#467)

Jasmine Nehema 1 , Shaghayegh Baghapour 2 , Shane M Hickey 1 , Stephen C Warren-Smith 2 3 , Wen Qi Zhang 2 3 , Shahraam A Vahid 2 , Sally E Plush 1
  1. Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
  2. Laser Physics and Photonic Devices Laboratories, University of South Australia, Mawson Lakes, South Australia, Australia
  3. Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia

Reactive species such as hydrogen sulphide and reactive oxygen species is a group of highly reactive chemicals that regulate the antioxidant defence system in biological systems.1  Oxidative stress conditions, resulting from an imbalance in the reactive species levels are associated with cancer, neurodegenerative diseases, and other pathologies.2 Measuring oxidative stress provides critical information on metabolism that can be used as an indicator for cancer. Recently, optical fibres have been used to develop compact, remote, and real-time sensing platforms.3 In this work, we are taking advantage of the nucleophilicity of the reactive species to reduce non fluorescent aromatic azides and boronate esters to fluorescent aromatic amines and phenols to develop novel HS- and H2O2 fibre based sensors.4 The first stage focused on the direct attachment of 1,8-naphthalimide to deliver a fluorescent sensors, where the attachment to the fibre resulted in an improved response time (less than 2 minutes) compared to in solution (30 minutes) [Figure 1. (a)].5  Surface characterization of the control and coated optical fibres was carried out using XPS, which demonstrated reproducibility of the coating process, with uniform coverage achieved. The next stage involved the use of the ‘antenna’ effect to develop a photobleaching resistant lanthanide sensors [Figure 1. (b)]. To achieve this, some 1,4,7,10-tetraazacyclododeacane lanthanide(III) complexes for fibre attachment were designed and synthesized, attached to fibre optic cables and their photophysics were explored.

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Figure 1. (a) A fibre optic cable coated with a hydrogen sulphide sensor shows a 90% increase in fluorescent signal in less than 2 minutes. (b) Lanthanide and antenna emission response from hydrogen peroxide detection

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