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Publications

G. Lotay, J. Henderson, W. N. Catford, F. A. Ali, S. Hallam, J. Berean, M. Spencer, N. Bernier, M. Williams, S. S Bhattacharjee, M Bowry, R Caballero-Folch, B. Davids, T. E. Drake, A. B. Garnsworthy, F. Ghazi Moradi, S. A. Gillespie, B. Greaves, E Kasanda, G. Hackman, B.K. Luna, D. Hymers, D. Levy, A. Mathews, Z Meisel, M. Moukaddam, D Muecher, B Olaizola, NA Orr, H.P. Patel, MM Rajabali, Y Saito, J. Smallcombe, C. E. Svensson, K. Whitmore (2022)Single neutron transfer on 23Ne and its relevance for the pathway of nucleosynthesis in astrophysical X-ray bursts, In: Physics Letters B833137361 Elsevier

We present new experimental measurements of resonance strengths in the astrophysical 23Al(p,γ)24Si reaction, constraining the pathway of nucleosynthesis beyond 22Mg in X-ray burster scenarios. Specifically, we have performed the first measurement of the (d,p) reaction using a radioactive beam of 23Ne to explore levels in 24Ne, the mirror analog of 24Si. Four strong single-particle states were observed and corresponding neutron spectroscopic factors were extracted with a precision of ∼20%. Using these spectroscopic factors, together with mirror state identifications, we have reduced uncertainties in the strength of the key ℓ = 0 resonance at Er = 157 keV, in the astrophysical 23Al(p,γ) reaction, by a factor of 4. Our results show that the 22Mg(p,γ)23Al(p,γ) pathway dominates over the competing 22Mg(α,p) reaction in all but the most energetic X-ray burster events (T>0.85 GK), significantly affecting energy production and the preservation of hydrogen fuel.

MICHAEL GEORGE SPENCER, Marco SACCHI, JEREMY ALLAM, S. Ravi P. Silva (2022)Resonant Quenching of Photoluminescence in Porphyrin – Nanocarbon Agglomerates, In: Cell reports physical science Elsevier

By adopting structural conformations with sub-nanometer precision, nature creates highly concentrated pigment-protein arrays to capture solar energy with high-efficiency. Synthetic analogues of such systems exhibit concentration dependent fluorescence quenching when approaching pigment concentrations of that seen in biological systems. Here we report on systems of acid functionalised multi-walled carbon nanotubes (o-MWCNT) and aminophenyl tetraporphyrins that create a novel synthetic pigment-scaffold complex. The complex does not follow the trend of typical fluorescence quenching. Our steady-state and time-resolved data suggest an optimal concentration that offers a luminescence enhancement compared to the expected standard Stern-Volmer quenching relationship. The quenching is modified by controlling 1 the pigment-distance via agglomerate size to near the upper limit for Dex-ter transfer of 10Å10˚10Å as confirmed by dynamic light scattering measurements and chromophore-chromophore nearest neighbour calculations. Our results highlight a potential synthetic complex with facile synthesis to investigate resonant electron transfer processes that do not follow traditional luminescence self-quenching relationships.

Youngchan Kim, Federico Bertagna, Edeline M. D’Souza, Derren J. Heyes, Linus O. Johannissen, Eveliny T. Nery, Antonio Pantelias, Alejandro Sanchez-Pedreño Jimenez, Louie Slocombe, Michael G. Spencer, Jim Al-Khalili, Gregory S. Engel, Sam Hay, Suzanne M. Hingley-Wilson, Kamalan Jeevaratnam, Alex R. Jones, Daniel R. Kattnig, Rebecca Lewis, Marco Sacchi, Nigel S. Scrutton, S. Ravi P. Silva, Johnjoe McFadden (2021)Quantum Biology: An Update and Perspective, In: Quantum Reports3(6)pp. 80-126 MDPI AG

Understanding the rules of life is one of the most important scientific endeavours and has revolutionised both biology and biotechnology. Remarkable advances in observation techniques allow us to investigate a broad range of complex and dynamic biological processes in which living systems could exploit quantum behaviour to enhance and regulate biological functions. Recent evidence suggests that these non-trivial quantum mechanical effects may play a crucial role in maintaining the non-equilibrium state of biomolecular systems. Quantum biology is the study of such quantum aspects of living systems. In this review, we summarise the latest progress in quantum biology, including the areas of enzyme-catalysed reactions, photosynthesis, spin-dependent reactions, DNA, fluorescent proteins, and ion channels. Many of these results are expected to be fundamental building blocks towards understanding the rules of life.