Ultrasensitive immunoassay for detection of Citrus tristeza virus in citrus sample using disposable microfluidic electrochemical device

Author(s)

Freitas, Tayane A. ^[1] ; Proenca, Camila A. ^[1] ; Baldo, Thaisa A. ^[1] ; Materon, Elsa M. ^[1] ; Wong, Ademar ^[1] ; Magnani, Rodrigo F. ^{[1, 2]} ; Faria, Ronaldo C. ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Chem, BR-13565905 Sao Carlos, SP - Brazil

^[2] Fundecitrus, Dept Pesquisa & Desenvolvimento, BR-14807040 Araraquara, SP - Brazil

• Document type: Journal article
• Source: Talanta; v. 205, DEC 1 2019.
• Web of Science Citations: 2

Abstract

Tristeza is a disease that affects citrus crops in general, caused by the Citrus tristeza virus (CTV). It is considered an economically important virus diseases in citrus, which is present in the main citrus producing regions all around the world. Early detection of CTV is crucial to avoid any epidemics and substantial economic losses for the citrus growers. Consequently, the development of rapid, accurate, and sensitive methods capable of detecting the virus in the early stages of the disease is highly desired. Based on that, a low-cost and rapid magneto-immunoassay methodology to detect the capsid protein from CTV (CP-CTV) was proposed. For this, magnetic beads were decorated with antibodies anti-CP-CTV and horseradish peroxidase enzyme (HRP) and applied for the capture and separation of CP-CTV from the sample solutions. The magnetically captured biomarker was detected using a simple disposable microfluidic electrochemical device (D mu FED) constructed by rapid prototyping technique and composed by an array of immunosensors. In D mu FED, the electrodes were modified with monoclonal antibody anti-CP-CTV and the detection was carried out using amperometry, based on the hydroquinone/H2O2 catalytic redox reaction due to the presence of HRP label in an immune-sandwich structure. The proposed immunoassay presented excellent linearity with a wide linear range of concentration of 1.95-10.0 x 10(3) fg mL(-1) and ultralow detection limit of 0.3 fg mL(1). The disposable device was successfully applied for the detection of Citrus tristeza virus in healthy and infected plant samples, where it showed good agreements with the comparative method of enzyme-linked immunosorbent assay (ELISA). The developed immunoassay methodology showed a sensitive and selective way in the detection of CTV. Hence, it can be considered as a promising analytical alternative for rapid and low-cost diagnosis of Tristeza disease in citrus. (AU)

• FAPESP's process: 16/00991-5 - Study of Detoxification Enzymes Interaction with chemotherapeutic drugs and its relationship with chemoresistance
• Grantee: Elsa María Materón Vásques
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 15/19890-1 - Development of methods for diagnosis of diseases using magnetic particles and an array of imunossensors in a disposable microfluidic system
• Grantee: Ronaldo Censi Faria
• Support type: Regular Research Grants
• FAPESP's process: 17/24053-7 - Development of simple electrochemical methods for the detection of biomarkers for the diagnosis of diseases
• Grantee: Ronaldo Censi Faria
• Support type: Regular Research Grants