Fabrication of Poly-l-lysine-Functionalized Graphene Quantum Dots for the Label-Free Fluorescent-Based Detection of Carcinoembryonic Antigen.
ACS Biomater Sci Eng
; 8(2): 470-483, 2022 02 14.
Article
em En
| MEDLINE
| ID: mdl-34967597
ABSTRACT
The diagnosis of tumor biomarkers is an attentive approach for the early detection and treatment of cancer. However, a cost-effective, simple, rapid, selective, and sensitive method is a basic prerequisite for diagnostic research. Herein, we present a novel fluorescence-based label-free sensing strategy for the sensitive and selective detection of carcinoembryonic antigen (CEA) using poly-l-lysine (PLL)-functionalized graphene quantum dots (GQDs). The GQDs were synthesized using a greener method by employing carbonized peanut shell (PNS) waste as a carbon source, and functionalization was accomplished using PLL (PLL-GQDs). The fluorescence stability of the PLL-GQDs was tested in a variety of solvent systems and pH solutions. When compared to nonfunctionalized GQDs (PNS-GQDs), prepared PLL-GQDs demonstrated increased fluorescence lifetime, high quantum yield, excellent photostability, biocompatibility, and greater cellular uptake. The PLL-GQDs with abundant surface amine and carboxylic groups showed selective interactions with an activated CEA antibody (CEA-Ab), resulting in the quenching of fluorescence signals. Because of the strong bioaffinity of CEA to the CEA-Ab, the antibody was unwrapped, resulting in the formation of an antibody-antigen complex and the recovery of fluorescence. As a result of this relationship, a turn "on-off-on" sensing mechanism with a strong response to CEA concentration (0.01 ng mL-1 to 100 µg mL-1) and a detection limit of 1.19 pg mL-1 was demonstrated. Furthermore, the fabricated CEA immunosensor (CEA-Ab@PLL-GQDs) performed admirably in real sample analysis, with an average recovery of 98.32%. The cellular uptake performance of PLL-GQDs was also demonstrated in the A427 cell lines, exhibiting a greater cellular uptake potential than PNS-GQDs. The cellular bioimaging study demonstrates that PLL-GQDs can be used for additional therapeutic and biological applications.
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Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
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Pontos Quânticos
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Grafite
Tipo de estudo:
Diagnostic_studies
/
Screening_studies
Idioma:
En
Revista:
ACS Biomater Sci Eng
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Índia