The role of non-trivial quantum mechanical effects in biology has been the subject of intense scrutiny over the past decade. Much of the focus on potential "quantum biology" has been on energy transfer processes in photosynthetic light harvesting systems. Ultrafast laser spectroscopy of several light harvesting proteins has uncovered coherent oscillations dubbed "quantum beats" that persist for hundreds of femtoseconds and are putative signatures for quantum transport phenomena. This review describes the language and basic quantum mechanical phenomena that underpin quantum transport in open systems such as light harvesting and photosynthetic proteins, including the photosystem reaction centre. Coherent effects are discussed in detail, separating various meanings of the term, from delocalized excitations, or excitons, to entangled states and coherent transport. In particular, we focus on the time, energy and length scales of energy transport processes, as these are critical in understanding whether or not coherent processes are important. The role played by the protein in maintaining chromophore systems is analysed. Finally, the spectroscopic techniques that are used to probe energy transfer dynamics and that have uncovered the quantum beats are described with reference to coherent phenomena in light harvesting.
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http://dx.doi.org/10.1007/s12551-018-0451-2 | DOI Listing |
Photosynth Res
January 2025
Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia.
The Orange Carotenoid Protein (OCP) is a unique water-soluble photoactive protein that plays a critical role in regulating the balance between light harvesting and photoprotective responses in cyanobacteria. The challenge in understanding OCP´s photoactivation mechanism stems from the heterogeneity of the initial configurations of its embedded ketocarotenoid, which in the dark-adapted state can form up to two hydrogen bonds to critical amino acids in the protein's C-terminal domain, and the extremely low quantum yield of primary photoproduct formation. While a series of experiments involving point mutations within these contacts helped us to identify these challenges, they did not resolve them.
View Article and Find Full Text PDFNatl Sci Rev
February 2025
State Key Laboratory of Millimeter Waves, School of Information Science and Engineering, Southeast University, Nanjing 210096, China.
With the rapid expansion of wireless networks, the deployment and long-term maintenance of distributed microwave terminals have become increasingly challenging. To address these issues, we present a bio-inspired microwave system to constitute passive and maintenance-free wireless networks. Drawing inspiration from vertebrate skeletons and skins, we employ stimuli-responsive polymer with tunable stiffness to support and protect sensitive electromagnetic structures, and synthesize self-healable skin-like polymer for system encapsulation.
View Article and Find Full Text PDFChem Sci
January 2025
Department of Chemical Sciences, Indian Institute of Science Education and Research Mohanpur 741246 Kolkata India
Developing a self-sensitized catalyst from earth-abundant elements, capable of efficient light harvesting and electron transfer, is crucial for enhancing the efficacy of CO transformation, a critical step in environmental cleanup and advancing clean energy prospects. Traditional approaches relying on external photosensitizers, comprising 4d/5d metal complexes, involve intermolecular electron transfer, and attachment of photosensitizing arms to the catalyst necessitates intramolecular electron transfer, underscoring the need for a more integrated solution. We report a new Cu(ii) complex, K[CuNDPA] (1[K(18-crown-6)]), bearing a dipyrrin amide-based trianionic tetradentate ligand, NDPA (HL), which is capable of harnessing light energy, despite having a paramagnetic Cu(ii) centre, without any external photosensitizer and photocatalytically reducing CO to CO in acetonitrile : water (19 : 1 v/v) with a TON as high as 1132, a TOF of 566 h and a selectivity of 99%.
View Article and Find Full Text PDFChemistry
January 2025
Yanshan University, Physics, Hebeidajie,438, 066004, Qinhuangdao, CHINA.
Identifying two-dimensional (2D) high-efficiency solar photovoltaic devices remains an urgent challenge in addressing current energy demands. Considering the limits of isolated 2D systems in photovoltaics, one most effective solution is stacking them into van der Waals heterostructures (vdWHs). However, the favorable factors for photovoltaics in vdWHs is still uncertain, nor the intrinsic principles is clear.
View Article and Find Full Text PDFChem Asian J
January 2025
CSIR-National Chemical Laboratory: CSIR National Chemical Laboratory, Catalysis and Inorganic Chemistry Division, Dr. Homi Bhabha Road, 411 008, Pune, INDIA.
Present work describes a sol-gel assisted one-pot synthesis of mesoporous Fe₂O₃-TiO₂ nanocomposites (TiFe) with different Ti:Fe ratios, and fabrication of Ag-integrated with TiFe nanocomposites (TiFeAg) by a chemical reduction method and demonstrated for high solar H2 generation activity in direct sunlight. Enhanced solar H2 production is attributed to the light absorption from entire UV+Visible region of solar spectrum combined with Schottky (Ag-semiconductor) and heterojunctions (TiO2-Fe2O3), as evidenced from HRTEM and various characterization studies. TiFeAg-2 thin film (1 wt% Ag-loaded TiFe-4) displayed the highest activity with a solar H2 yield of 7.
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