One-photon excited photoluminescence of gold nanospheres and its application in prostate specific antigen detection via fluorescence correlation spectroscopy (FCS).
Talanta
; 228: 122242, 2021 Jun 01.
Article
en En
| MEDLINE
| ID: mdl-33773714
ABSTRACT
Gold nanoparticles are known to exhibit appealing intrinsic plasmon-modulated photoluminescence (PL) properties which can be explored in various fluorescence-based sensing applications. In this paper, we evaluate the PL of different-sized gold nanospheres (AuNSs) under one-photon excitation (1PE) and develop a sensitive homogeneous immunoassay for the detection of prostate specific antigen (PSA) in colloidal suspension via fluorescence correlation spectroscopy (FCS). The 1PE PL of AuNSs of three different sizes are evaluated in solution phase under excitation at 405 nm via steady-state fluorescence spectroscopy measurements, while FCS analysis emphasizes the feasibility of using 1PE PL properties to monitor their diffusion behavior. Fluorescence lifetime imaging microscopy (FLIM) assays coupled with PL spectral profile analysis performed on single-particles-like structures conform the plasmonic origin of the detected PL and validate their potential of synthesized AuNSs as fluorescent probes in bioimaging and bioassays. Finally, to the best of our knowledge, we provide the first demonstration of the successful use of the 1PE PL of the synthesized AuNSs as probes for the FCS-based one-step label-free sensitive optical detection of PSA biomarker. The approach consisting in monitoring the diffusion of the AuNSs-oligomers induced by the interaction of anti-PSA-conjugated AuNSs with PSA molecules is successfully validated for the detection of PSA levels as low as 4.4 ng/ml in solution. Considering that the development of rapid, efficient and label-free biosensing methods is of continuous interest nowadays, we are confident that our results may have a strong impact on medicine towards more efficient, sensitive and reliable diagnosis.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Nanopartículas del Metal
/
Nanosferas
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
/
Male
Idioma:
En
Revista:
Talanta
Año:
2021
Tipo del documento:
Article