New conductive filament ready-to-use for 3D-printing electrochemical (bio)sensors: Towards the detection of SARS-CoV-2

Author(s)

Stefano, Jessica Santos ^[1] ; Guterres e Silva, Luiz Ricardo ^[1] ; Rocha, Raquel Gomes ^[2] ; Brazaca, Lais Canniatti ^{[3, 4]} ; Richter, Eduardo Mathias ^{[2, 3]} ; Abarza Munoz, Rodrigo Alejandro ^{[2, 3]} ; Janegitz, Bruno Campos ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Nat Sci Math & Educ, BR-13600970 Araras, SP - Brazil

^[2] Univ Fed Uberlandia, Inst Chem, BR-38400902 Uberlandia, MG - Brazil

^[3] Natl Inst Sci & Technol Bioanal INCTBio, BR-13083970 Campinas, SP - Brazil

^[4] Univ Sao Paulo, Sao Carlos Inst Phys, Nanomed & Nanotoxicol Grp, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Analytica Chimica Acta; v. 1191, JAN 25 2022.
• Web of Science Citations: 0

Abstract

The 3D printing technology has gained ground due to its wide range of applicability. The development of new conductive filaments contributes significantly to the production of improved electrochemical devices. In this context, we report a simple method to producing an efficient conductive filament, containing graphite within the polymer matrix of PLA, and applied in conjunction with 3D printing technology to generate (bio)sensors without the need for surface activation. The proposed method for producing the conductive filament consists of four steps: (i) mixing graphite and PLA in a heated reflux system; (ii) recrystallization of the composite; (iii) drying and; (iv) extrusion. The produced filament was used for the manufacture of electrochemical 3D printed sensors. The filament and sensor were characterized by physicochemical techniques, such as SEM, TGA, Raman, FTIR as well as electrochemical techniques (EIS and CV). Finally, as a proof-of-concept, the fabricated 3D-printed sensor was applied for the determination of uric acid and dopamine in synthetic urine and used as a platform for the development of a biosensor for the detection of SARS-CoV-2. The developed sensors, without pre-treatment, provided linear ranges of 0.5-150.0 and 5.0-50.0 mu mol L-1, with low LOD values (0.07 and 0.11 mu mol L-1), for uric acid and dopamine, respectively. The developed biosensor successfully detected SARS-CoV-2 S protein, with a linear range from 5.0 to 75.0 nmol L-1 (0.38 mu g mL(-1) to 5.74 mu g mL(-1)) and LOD of 1.36 nmol L-1 (0.10 mu g mL(-1)) and sensitivity of 0.17 mu A nmol(-1) L (0.01 mu A mu g(-1) mL). Therefore, the lab-made produced and the ready-to-use conductive filament is promising and can become an alternative route for the production of different 3D electrochemical (bio)sensors and other types of conductive devices by 3D printing. (C) 2021 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 17/21097-3 - Bee-agriculture interactions: perspectives to sustainable use
• Grantee: Osmar Malaspina
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 18/19750-3 - Exploring C4D detection for the development of innovative and low-cost microfluidic biosensors
• Grantee: Laís Canniatti Brazaca
• Support Opportunities: Scholarships in Brazil - Post-Doctoral