Reusable and highly sensitive SERS immunoassay utilizing gold nanostars and a cellulose hydrogel-based platform

• Tipo: Artigo em Revista Científica Internacional
• Data: 2021

Autores

Oliveira, MJ (Autor) Outra; Cunha, I (Autor) Outra; M. Peixoto de Almeida (Autor) FCUP; Calmeiro, T (Autor) Outra; Fortunato, E (Autor) Outra; Martins, R (Autor) Outra; Pereira, L (Autor) Outra; Byrne, HJ (Autor) Outra; Eulalia Pereira (Autor) FCUP; Aguas, H (Autor) Outra; Franco, R (Autor) Outra

Revista

Título: Journal of Materials Chemistry B

Vol. 9

Páginas: 7516-7529

ISSN: 2050-7518

Editora: Royal Society of Chemistry

Indexação

ISI Web of Knowledge - 13 Citações

Scopus - 14 Citações

Outras Informações

ID Authenticus: P-00V-ADJ

DOI: 10.1039/d1tb01404h

Abstract (EN): The development of robust and sensitive point-of-care testing platforms is necessary to improve patient care and outcomes. Surface-enhanced Raman scattering (SERS)-based immunosensors are especially suited for this purpose. Here, we present a highly sensitive and selective SERS immunoassay, demonstrating for example the detection of horseradish peroxidase (HRP), in a sandwich format. The strength of our biosensor lies in merging: (i) SERS-immunotags based on gold nanostars, allowing exceptional intense SERS from attached Raman probes, covalent attachment of anti-HRP antibodies by a simple chemical method providing exceptional antigen binding activity; (ii) the ease of preparation of the capture platform from a regenerated cellulose-based hydrogel, a transparent material, ideal for microfluidics applications, with low background fluorescence and Raman signal, particularly suited for preserving high activity of the covalently bound anti-HRP antibodies. The sandwich complexes formed were characterised by atomic force microscopy, and by scanning electron microscopy coupled with electron diffraction spectroscopy; and (iii) the robustness of the simple Classical Least Squares method for SERS data analysis, resulting in superior discrimination of SERS signals from the background and much better data fitting, compared to the commonly used peak integral method. Our SERS immunoassay greatly improves the detection limits of traditional enzyme-linked immunosorbent assay approaches, and its performance is better or comparable to those of existing SERS-based immunosensors. Our approach successfully overcomes the main challenges of application at point-of-care, including increasing reproducibility, sensitivity, and specificity, associated with an environmentally friendly and robust design. Also, the proposed design withstands several cycles of regeneration, a feature absent in paper-SERS immunoassays and this opens the way for sensitive multiplexing applications on a microfluidic platform.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 14