Enhanced performance of impedimetric immunosensors to detect SARS-CoV-2 with bare gold nanoparticles and graphene acetic acid

Author(s):Show less -

Hensel, Rafael C. ; Di Vizio, Biagio ; Materon, Elsa M. ; Shimizu, Flavio M. ; Angelim, Monara Kaelle S. C. ; de Souza, Gabriela F. ; Modena, Jose L. P. ; Moraes-Vieira, Pedro M. M. ; de Azevedo, Ricardo B. ; Litti, Lucio ; Agnoli, Stefano ; Casalini, Stefano ; Oliveira Jr, Osvaldo N.

• Document type: Journal article
• Source: Talanta; v. 281, p. 9-pg., 2024-09-25.

Abstract

Immunosensors based on electrical impedance spectroscopy allow for label-free, real-time detection of biologically relevant molecules and pathogens, without requiring electro-active materials. Here, we investigate the influence of bare gold nanoparticles (AuNPs), synthesized via laser ablation in solution, on the performance of an impedimetric immunosensor for detecting severe acute respiratory syndrome coronavirus (SARS-CoV-2). Graphene acetic acid (GAA) was used in the active layer for immobilizing anti-SARS-CoV-2 antibodies, owing to its high density of carboxylic groups. Immunosensors incorporating AuNPs exhibited superior performance compared to those relying solely on GAA, achieving a limit of detection (LoD) of 3 x 10-20 g/mL to detect the Spike Receptor Binding Domain (RBD) protein of SARS-CoV-2 and of 2 PFU/mL for inactivated virus. Moreover, these immunosensors presented high selectivity against the H1N1 influenza virus. We anticipate that this platform will be versatile and applicable in the early diagnosis of various diseases and viral infections, thereby facilitating Point-of-Care testing. (AU)

• FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/15095-0 - Biosensors made with polymer films incorporating metallic nanoparticles for clinical diagnosis
• Grantee: Rafael Cintra Hensel Ferreira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral