Nanostructured functional peptide films and their application in C-reactive protein immunosensors

Author(s)

Piccoli, Julia P. ^{[1, 2]} ; Soares, Andrey C. ^{[1, 3]} ; Oliveira, Jr., Osvaldo N. ^[1] ; Cilli, Eduardo M. ^[4]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Inst Phys, BR-13566590 Sao Carlos, SP - Brazil

^[2] Inst Vita Nova, Rua Barao Itapura 135, Parque Odimar, BR-13186432 Sao Paulo - Brazil

^[3] Embrapa Instrumentacao, Nanotechnol Natl Lab Agr LNNA, BR-13560970 Sao Carlos, SP - Brazil

^[4] Sao Paulo State Univ, Inst Chem, BR-14800060 Araraquara, SP - Brazil

• Document type: Journal article
• Source: BIOELECTROCHEMISTRY; v. 138, APR 2021.
• Web of Science Citations: 0

Abstract

Peptides with an active redox molecule are incorporated into nanostructured films for electrochemical biosensors with stable and controllable physicochemical properties. In this study, we synthesized three ferrocene (Fc)-containing peptides with the sequence Fc-Glu-(Ala)(n)-Cys-NH2, which could form self-assembled monolayers on gold and be attached to antibodies. The peptide with two alanines (n = 2) yielded the immunosensor with the highest performance in detecting C-reactive protein (CRP), a biomarker of inflammation. Using electrochemical impedance-derived capacitive spectroscopy, the limit of detection was 240 pM with a dynamic range that included clinically relevant CRP concentrations. With a combination of electrochemical methods and polarization-modulated infrared reflection-absorption spectroscopy, we identified the chemical groups involved in the antibody-CRP interaction, and were able to relate the highest performance for the peptide with n = 2 to chain length and efficient packing in the organized films. These strategies to design peptides and methods to fabricate the immunosensors are generic, and can be applied to other types of biosensors, including in low cost platforms for point-of -care diagnostics. (C) 2020 Elsevier B.V. All rights reserved. (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: 13/07600-3 - CIBFar - Center for Innovation in Biodiversity and Drug Discovery
• Grantee: Glaucius Oliva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 18/18953-8 - Nanostructured films applied in microfluidic biosensors to mastitis detection
• Grantee: Andrey Coatrini Soares
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/24839-0 - Nanoelectronics and nanoscale electrochemistry: fundaments and applications
• Grantee: Paulo Roberto Bueno
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/18231-2 - Study of self-assembled monolayers of peptides and their application in immunosensors for detecting Pancreatic Cancer biomarkers
• Grantee: Júlia Pinto Piccoli
• Support Opportunities: Scholarships in Brazil - Post-Doctoral