Polyallylamine hydrochloride coating enhances the fluorescence emission of human serum albumin encapsulated gold nanoclusters

Russell, Ben Allan and Jachimska, Barbara and Chen, Yu (2018) Polyallylamine hydrochloride coating enhances the fluorescence emission of human serum albumin encapsulated gold nanoclusters. Journal of Photochemistry and Photobiology B: Biology, 187. pp. 131-135. ISSN 1011-1344 (https://doi.org/10.1016/j.jphotobiol.2018.08.018)

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Abstract

Protein encapsulated gold nanoclusters have received much attention due to the possibility of using them as a non-toxic fluorescent probe or marker for biomedical applications, however one major disadvantage currently is their low brightness and quantum yield in comparison to currently used fluorescent markers. A method of increasing the fluorescence emission of Human Serum Albumin (HSA) encapsulated gold nanoclusters (AuNCs) via a Polyallylamide hydrochloride (PAH) coating is described. PAH molecules with a molecular weight of ~17,500 Da were found to enhance the fluorescence emission of HSA-AuNCs by 3-fold when the protein/polymer concentration ratio is 2:1 in solution. Interestingly, the fluorescence lifetime of the AuNCs was found to decrease while the native tryptophan (TRP) fluorescence lifetime also decreased during the fluorescence emission intensity enhancement caused by the PAH binding. Coinciding with the decrease in fluorescence lifetime, the zeta potential of the system was observed to be zero during maximum fluorescence intensity enhancement, causing the formation of large aggregates. These results suggest that PAH binds to the HSA-AuNCs acting as a linker; causing aggregation and rigidification, which results in a decrease in separation between native TRP of HSA and AuNCs; improving Förster Resonance Energy Transfer (FRET) and increasing the fluorescence emission intensity. These findings are critical to the development of brighter protein encapsulated AuNCs.

ORCID iDs

Russell, Ben Allan ORCID logoORCID: https://orcid.org/0000-0002-8740-6040, Jachimska, Barbara and Chen, Yu;
  • Item type:Article
    ID code:65297
    Dates:
    Date
    Event
    31 October 2018
    Published
    18 August 2018
    Published Online
    15 August 2018
    Accepted
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:29 Aug 2018 10:47
    Last modified:11 Nov 2024 12:05
    URI:https://strathprints.strath.ac.uk/id/eprint/65297
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