Optimized PAH/Folic acid layer-by-layer films as an electrochemical biosensor for the detection of folate receptors

Author(s)

Correia, Abilene Rodrigues ^[1] ; Sampaio, Isabella ^[1] ; Comparetti, Edson Jose ^[1] ; Silva Vieira, Nirton Cristi ^{[2, 1]} ; Zucolotto, Valtencir ^[1]

Affiliation

^[1] Univ Sao Paulo, GNano Nanomed & Nanotoxicol Grp, Sao Carlos Inst Phys, CP 369, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Paulo, Inst Sci & Technol, BR-12231280 Sao Jose Dos Campos, SP - Brazil

• Document type: Journal article
• Source: BIOELECTROCHEMISTRY; v. 137, FEB 2021.
• Web of Science Citations: 0

Abstract

Folate receptor alpha (FR-alpha) is a glycoprotein overexpressed in tumor cell surfaces, especially in gynecologic cancers, and can be used as a biomarker for diagnostics. Currently, FRa is quantified by positron emission tomography (PET) or fluorescence imaging techniques. However, these methods are costly and time-consuming. We report on the development of an electrochemical biosensor for FR alpha detection based on the use of nanostructured layer-by-layer (LbL) films as modified electrodes. Multilayer films were deposited on indium tin oxide (ITO) electrodes by the alternately assembling of positively charged polyallylamine hydrochloride (PAH) and negatively charged folic acid (FA), used as the biorecognition element. UV-vis and FTIR spectroscopies revealed the successful PAH and FA adsorption on ITO. Devices performance was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The {[}PAH/FA] films presented a good reproducibility (RSD of 1.12%) and stability when stored in the Tris-HCl solution (RSD 6.7%). The biosensor electrochemical response exhibited a linear relationship with FRa concentration in the range from 10 to 40 nM. The limit of detection reached for CV and EIS measurements were 0.7 and 1.5 nM, respectively. As a proof-of-concept, we show that the devices can differenciate tumor cells from healthy cell, showing an excellent selectivity. The biosensor device based on {[}PAH/FA] films represents a promising strategy for a simple, rapid, and low-cost cancer diagnosis through FRa quantification on the surface of cancer cells. (C) 2020 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 18/07508-3 - Exploring the electrical and optical properties of graphene derivatives for the detection of cyanotoxins
• Grantee: Nirton Cristi Silva Vieira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/12670-4 - Synthesis of lipid nanocarriers for modulation of tumor and immunocompetent cells
• Grantee: Edson José Comparetti
• Support Opportunities: Scholarships in Brazil - Doctorate