Probing the excited state dynamics of Venus: origin of dual-emission in fluorescent proteins

Dhamija, Shaina; Thakur, Bhishem; Guptasarma, Purnananda; De, Arijit K.

doi:10.1039/c7fd00187h

Cited by 14 publications

(13 citation statements)

References 15 publications

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“…Differential absorption spectra (obtained by blocking alternate pump pulses) were collected by varying the pump-probe time delay keeping 1 s integration time (i.e., averaging over 500 laser shots) and maintaining magic-angle polarization between the pump and probe pulses. A detailed description of the pump-probe setup is given elsewhere. ,, …”

Section: Methodsmentioning

confidence: 99%

Cation-Dependent Hot Carrier Cooling in the Lead-Free Bismuth Halide A₃Bi₂I₉ (A = FA, MA, and Cs) Perovskite

et al. 2021

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Lead-free halide perovskites, as environment-friendly materials, have received critical interest in photovoltaic applications. In this regard, the bismuth halide perovskites demonstrate better stability under ambient conditions than lead halide perovskites and consequently remain one of the critical areas for the development of lead-free absorber materials. The steady-state optical properties are widely investigated in these bismuth halide perovskites, but excited-state charge carrier dynamics such as hot carrier relaxation remain elusive. However, it is crucial to investigate the rapid relaxation of above band gap “hot” carriers as it restricts the fundamental efficiency limit in the perovskite solar cells. Here, we demonstrate the cation-dependent hot carrier cooling in the lead-free A3Bi2I9 [A = FA (formamidinium), MA (methylammonium), and Cs (cesium)] perovskite by using femtosecond transient absorption spectroscopy. These lead-free perovskites were fabricated from gamma-butyrolactone (γ-GBL) solvent to ensure uniformity and continuity of the as-grown film and were well characterized by XRD, SEM, and steady-state absorption and photoluminescence spectroscopy. With varying A-cations, we observe that the hot-hole relaxation is slowest in the all-inorganic perovskite Cs3Bi2I9 (12.83 ps) and hot electron relaxation is slowest in the hybrid MA3Bi2I9 perovskite (6.42 ps) at the same excitation energy. The observed strong dependence of carrier cooling on cation composition is explained by the interaction between the different organic cations (A = FA, MA, and Cs) with the Pb–Br frameworks. Our study provides an opportunity to understand the effect of cations on the excited-state carrier dynamics, especially the hot carrier relaxation in the bismuth halide perovskites. This will pave the way for designing hot carrier-based high-efficient lead-free perovskite photovoltaic devices.

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Section: Methodsmentioning

confidence: 99%

Cation-Dependent Hot Carrier Cooling in the Lead-Free Bismuth Halide A₃Bi₂I₉ (A = FA, MA, and Cs) Perovskite

et al. 2021

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“…Details of the customized femtosecond transient absorption spectrometer (TAS, Newport) are discussed elsewhere. [26,27] The ultrashort pulse centered at 670 nm having~43 fs pulse-width at 1 kHz repetition rate from a commercial non-collinear optical parametric amplifier (Topas White, Light conversion), pumped by a Ti: Sapphire regenerative amplifier centered on~800 nm having~54 fs pulse-width (Libra, Coherent), is used as pump to excite the Q y band of Chl-a. At the pump laser wavelength (centered at 670 nm), the optical densities of monomer, rodshaped and micellar structures are 0.192, 0.148 and 0.125, respectively.…”

Section: Transient Absorption Studiesmentioning

confidence: 99%

Unravelling the Role of Water in Ultrafast Excited‐State Relaxation Dynamics within Nano‐Architectures of Chlorophyll a

Silori

Chawla

2020

ChemPhysChem

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Water plays a pivotal role in structural stability of supramolecular pigment assemblies designed for natural light harvesting (for example, chlorosome antenna complex) as well as their artificial analogs. However, the dynamic role of water in the context of excite‐state relaxation has not been explored till date, which we report here. Using femtosecond transient absorption spectroscopy, we investigate the excited‐state dynamics of two types of nano‐scale assemblies of chlorophyll a with different structural motifs, rod‐shaped and micellar assemblies, that depend on the water content. We show how water participates in excess energy dissipation by vibrational cooling of the non‐thermally populated Qy band at different rates in different types of clusters but exhibits no polar solvation dynamics. For the micelles, we observe a bifurcation of stimulated emission line shape, whereas a positive‐to‐negative switching of differential absorption is observed for the rods; both these observations are correlated with their specific structural aspects. Density functional theory calculations reveal two possible stable ground state geometries of dimers, accounting for the bifurcation of line shape in micelles. Thus, our study elucidates water‐mediated structure–function relationship within these pigment assemblies.

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“…The phenol form of the chromophore is fluorescent at lower pH values, but its emission maximum is at 510 nm (Figure S3D). As such, we speculate that, like avGFP, phiYFP can undergo ESPT from the chromophore Y66 to a proton acceptor in the chloride binding pocket to generate the fluorescent phenolate form of the chromophore. − The turn-on emission response is unique to phiYFP and is not observed with avYFP-H148Q (Figures S8).…”

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confidence: 99%

Discovery and Characterization of a Naturally Occurring, Turn-On Yellow Fluorescent Protein Sensor for Chloride

2018

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Fluorescent proteins have been extensively engineered and applied as optical indicators for chloride in a variety of biological contexts. Surprisingly, given the biodiversity of fluorescent proteins, a naturally occurring chloride sensor has not been reported to date. Here, we present the identification and spectroscopic characterization of the yellow fluorescent protein from the jellyfish Phialidium sp. (phiYFP), a rare example of a naturally occurring, excitation ratiometric, and turn-on fluorescent protein sensor for chloride. Our results show that chloride binding tunes the pKa of the chromophore Y66 and shifts the equilibrium from the fluorescent phenolate form to the weakly fluorescent phenol form. The latter likely undergoes excited state proton transfer to generate a turn-on fluorescence response that is pH dependent. Moreover, anion selectivity and mutagenesis in the chloride binding pocket provide additional evidence for the proposed chloride sensing mechanism. Given these properties, we anticipate that phiYFP, with further engineering, could be a new tool for imaging cellular chloride dynamics.

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Probing the excited state dynamics of Venus: origin of dual-emission in fluorescent proteins

Cited by 14 publications

References 15 publications

Cation-Dependent Hot Carrier Cooling in the Lead-Free Bismuth Halide A₃Bi₂I₉ (A = FA, MA, and Cs) Perovskite

Cation-Dependent Hot Carrier Cooling in the Lead-Free Bismuth Halide A₃Bi₂I₉ (A = FA, MA, and Cs) Perovskite

Unravelling the Role of Water in Ultrafast Excited‐State Relaxation Dynamics within Nano‐Architectures of Chlorophyll a

Discovery and Characterization of a Naturally Occurring, Turn-On Yellow Fluorescent Protein Sensor for Chloride

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Probing the excited state dynamics of Venus: origin of dual-emission in fluorescent proteins

Cited by 14 publications

References 15 publications

Cation-Dependent Hot Carrier Cooling in the Lead-Free Bismuth Halide A3Bi2I9 (A = FA, MA, and Cs) Perovskite

Cation-Dependent Hot Carrier Cooling in the Lead-Free Bismuth Halide A3Bi2I9 (A = FA, MA, and Cs) Perovskite

Unravelling the Role of Water in Ultrafast Excited‐State Relaxation Dynamics within Nano‐Architectures of Chlorophyll a

Discovery and Characterization of a Naturally Occurring, Turn-On Yellow Fluorescent Protein Sensor for Chloride

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Product

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Cation-Dependent Hot Carrier Cooling in the Lead-Free Bismuth Halide A₃Bi₂I₉ (A = FA, MA, and Cs) Perovskite

Cation-Dependent Hot Carrier Cooling in the Lead-Free Bismuth Halide A₃Bi₂I₉ (A = FA, MA, and Cs) Perovskite