Correlative extinction and single fluorophore bleaching microscopy for ligand quantification on gold nanoparticles

التفاصيل البيبلوغرافية
العنوان: Correlative extinction and single fluorophore bleaching microscopy for ligand quantification on gold nanoparticles
المؤلفون: Slesiona, Nicole, Payne, Lukas, Pope, Iestyn, Borri, Paola, Langbein, Wolfgang, Watson, Peter
سنة النشر: 2022
المجموعة: Condensed Matter
Physics (Other)
Quantitative Biology
مصطلحات موضوعية: Physics - Optics, Condensed Matter - Mesoscale and Nanoscale Physics, Quantitative Biology - Quantitative Methods
الوصف: Nanoparticles (NPs) are promising therapeutic delivery agents, yet it is increasingly apparent that the number and manner of presentation of cell binding ligands on the NP can affect the eventual fate of the therapeutic. Whenever NPs are conjugated with biomolecules, a heterogenous population of decorated NPs will be produced and the details of the subpopulations of particle-ligand structures needs to be characterised for a reliable interpretation of NP-based data. We report an optical microscopy method to quantitatively evaluate the conjugation on a single particle basis in samples consisting of gold NPs (GNPs) decorated with human holo-transferrin fluorescently labelled with Alexa647 (Tf). We employed widefield fluorescence and extinction microscopy on NP-ligand constructs sparesly deposited onto a glass surface, alongside a correlative analysis which spatially co-localises diffraction-limited sources of fluorescence with the optical extinction by individual GNPs. A photobleaching step analysis of the fluorescence emission was employed to estimate the number of fluorophores contributing to the detected emission rate. The method quantifies the number of fluorescent biomolecules attached per GNP, the numbers of unconjugated GNPs and unbound Tf present within the mixed population, and the size and intraparticle clustering propensity of conjugated GNPs. We found a high variability in the number of Tf ligands per GNP within the GNP population, when analysed at the single-particle level, unraveling a non-trivial statistical distribution not accessible in ensemble averaged approaches
نوع الوثيقة: Working Paper
DOI: 10.1002/admi.202300568
URL الوصول: http://arxiv.org/abs/2210.00942
رقم الأكسشن: edsarx.2210.00942
قاعدة البيانات: arXiv