Role of Tryptophan in Protein–Nanocrystals Interaction: Energy or Charge Transfer

2018 ◽  
Vol 233 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Mona Mittal ◽  
Saurabh Gautam ◽  
Pramit Kumar Chowdhury ◽  
Shashank Deep ◽  
Sameer Sapra
Keyword(s):  
Charge Transfer ◽  
Steady State ◽  
Semiconductor Nanocrystals ◽  
Binding Model ◽  
Time Resolved ◽  
Tryptophan Residues ◽  
Mechanism Of Interaction ◽  
Pl Intensity ◽  
Time Resolved Photoluminescence

Abstract The understanding of the interaction between the semiconductor nanocrystals (NCs) and the proteins are essential for design and fabrication of nanocomposites for application in the field of biotechnology. Herein, we have studied the interaction between CdTe NCs and the proteins by steady-state and time-resolved photoluminescence (PL) spectroscopy. The steady-state PL intensity of CdTe NCs is quenched and enhanced in the presence of lysozyme and bovine serum albumin, respectively. However, the PL intensity of CdTe NCs is not affected with α-synuclein, indicating the role of tryptophan moiety in the protein–NCs interaction. The detailed analysis of PL data allows us to elucidate the dominant mechanism of interaction, i.e. charge or energy transfer, depending on the location of tryptophan residues in the protein. Assuming a Poisson statistic of lysozymes around NCs, the Poisson binding model is used to understand the kinetics of charge transfer from CdTe NCs to the lysozyme. It provides the average number of lysozymes present on the surface of one CdTe NC.

Influence of Electron-withdrawing Substituents on Photoelectrochemical Surface Phenomena at Phthalocyanine Thin Film Electrodes

1999 ◽  
Vol 03 (06) ◽  
pp. 444-452 ◽  
Author(s):  
TORSTEN OEKERMANN ◽  
DERCK SCHLETTWEIN ◽  
NILS I. JAEGER ◽  
DIETER WÖHRLE
Keyword(s):  
Charge Transfer ◽  
Steady State ◽  
Electrolyte Concentration ◽  
Surface States ◽  
Surface Phenomena ◽  
Time Resolved ◽  
Photogenerated Electrons ◽  
Millisecond Range ◽  
Electron Withdrawing Substituents

The influence of electron-withdrawing substituents on the photoelectrochemical properties of phthalocyanines is shown in a comparison between hexadecafluorophthalocyaninatozinc(II) ( F 16 PcZn ) and the unsubstituted phthalocyaninatozinc(II) ( PcZn ). The role of surface states in the photoelectrochemistry of both materials has been investigated by time-resolved photocurrent measurements in the millisecond range. The charging and discharging of surface states could clearly be seen as spikes at the beginning and the end of illumination. Surface states were filled with photogenerated electrons at PcZn and with photogenerated holes at F 16 PcZn . In the steady state under illumination only cathodic photocurrents were detected at PcZn , while at F 16 PcZn both cathodic and anodic photocurrents were observed. An adsorption step of electroactive species prior to the charge transfer was derived from the dependence of the steady state photocurrents on the electrolyte concentration for both materials. The concentration dependence of the charging and discharging currents, however, showed that charge transfer from surface states to the electrolyte occurs at PcZn , while at F 16 PcZn the surface states only represent recombination centres.

scholarly journals Horizontal versus vertical charge and energy transfer in hybrid assemblies of semiconductor nanoparticles

2012 ◽  
Vol 3 ◽  
pp. 629-636 ◽  
Author(s):  
Gilad Gotesman ◽  
Rahamim Guliamov ◽  
Ron Naaman
Keyword(s):  
Energy Transfer ◽  
Charge Transfer ◽  
Horizontal Plane ◽  
Quartz Substrate ◽  
Vertical Direction ◽  
Time Resolved ◽  
Transfer Processes ◽  
Donor And Acceptor ◽  
Hybrid Assemblies ◽  
Time Resolved Photoluminescence

We studied the photoluminescence and time-resolved photoluminescence from self-assembled bilayers of donor and acceptor nanoparticles (NPs) adsorbed on a quartz substrate through organic linkers. Charge and energy transfer processes within the assemblies were investigated as a function of the length of the dithiolated linker (DT) between the donors and acceptors. We found an unusual linker-length-dependency in the emission of the donors. This dependency may be explained by charge and energy transfer processes in the vertical direction (from the donors to the acceptors) that depend strongly on charge transfer processes occurring in the horizontal plane (within the monolayer of the acceptor), namely, parallel to the substrate.

Steady state and time-resolved photoluminescence properties of alternating polyfluorene copolymers

2003 ◽  
Vol 135-136 ◽  
pp. 387-388 ◽  
Author(s):  
A. Charas ◽  
J. Morgado ◽  
L. Alcácer ◽  
J.M.G. Martinho ◽  
F. Cacialli
Keyword(s):  
Steady State ◽  
Photoluminescence Properties ◽  
Time Resolved ◽  
Time Resolved Photoluminescence

scholarly journals Влияние условий роста и уровня легирования на кинетику люминесценции слоев Ge : Sb, выращенных на кремнии

2020 ◽  
Vol 54 (7) ◽  
pp. 685
Author(s):  
Д.В. Юрасов ◽  
Н.А. Байдакова ◽  
А.Н. Яблонский ◽  
А.В. Новиков
Keyword(s):  
Doping Level ◽  
Room Temperature ◽  
Carrier Lifetime ◽  
Growth Conditions ◽  
Published Data ◽  
Rapid Thermal Anneal ◽  
Time Resolved ◽  
Light Emitting ◽  
Pl Intensity ◽  
Time Resolved Photoluminescence

Light-emitting properties of Ge-on-Si(001) layers doped by Sb were studied by stationary and time-resolved photoluminescence (PL) at room temperature. It was obtained that the PL intensity of n-Ge/Si(001) structures is maximized when the doping level is close to the equilibrium solubility of Sb in Ge (~1019 cm-3) which is in accordance with the previously published data. Time-resolved studies of the direct-related PL signal have shown that both the donor density and the growth conditions of doped layer, in particular, the growth temperature influence the PL kinetics. It was obtained that the increase of doping level leads to the decrease of the characteristic carrier lifetime. Moreover, usage of low growth temperatures which is needed to form the doped n-Ge layers also results in shortening of the carrier lifetime as compared with Ge layers grown at high temperatures. It was found that rapid thermal anneal at proper conditions could partially compensate the above mentioned detrimental effects and lead to the increase of both the PL intensity and carrier lifetime.

Photochemistry of triphenylamine (TPA) in homogeneous solution and the role of transient N-phenyl-4a,4b-dihydrocarbazole. A steady-state and time-resolved investigation.

2021 ◽  
Author(s):  
Stefano Protti ◽  
Mariella Mella ◽  
Sergio Mauricio Bonesi
Keyword(s):  
Steady State ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Homogeneous Solution ◽  
Laser Flash ◽  
Time Resolved ◽  
Homogeneous Media

Abstract. The photoreactivity of triphenylamine in homogeneous media has been investigated by means of laser flash photolysis spectroscopy and preparative experiments. The goal of this study consists in the evaluation...

Tuning the excited-state deactivation pathways of dinuclear ruthenium(ii) 2,2′-bipyridine complexes through bridging ligand design

2020 ◽  
Vol 49 (24) ◽  
pp. 8096-8106 ◽  
Author(s):  
Simon Cerfontaine ◽  
Ludovic Troian-Gautier ◽  
Sara A. M. Wehlin ◽  
Frédérique Loiseau ◽  
Emilie Cauët ◽  
...  
Keyword(s):  
Excited State ◽  
Steady State ◽  
Variable Temperature ◽  
Ligand Design ◽  
Binuclear Complexes ◽  
Time Resolved ◽  
Bridging Ligand ◽  
Dinuclear Ruthenium ◽  
Photophysical Study ◽  
Time Resolved Photoluminescence

A detailed photophysical study of binuclear complexes was performed using steady-state and time-resolved photoluminescence measurements at variable temperature. The results were compared with the prototypical [Ru(bpy)3]2+.

Steady state and time resolved photoluminescence properties of CuInS2/ZnS quantum dots in solutions and in solid films

2015 ◽  
Vol 167 ◽  
pp. 333-338 ◽  
Author(s):  
Nikolaos Droseros ◽  
Kostas Seintis ◽  
Mihalis Fakis ◽  
Spiros Gardelis ◽  
Androula G. Nassiopoulou
Keyword(s):  
Quantum Dots ◽  
Steady State ◽  
Photoluminescence Properties ◽  
Time Resolved ◽  
Solid Films ◽  
Time Resolved Photoluminescence
Sign in / Sign up

Export Citation Format

Share Document