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Pradela-Filho LA, Araújo DAG, Ataide VN, Meloni GN, Paixão TRLC. Challenges faced with 3D-printed electrochemical sensors in analytical applications. Anal Bioanal Chem 2024; 416:4679-4690. [PMID: 38664267 DOI: 10.1007/s00216-024-05308-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 04/10/2024] [Accepted: 04/15/2024] [Indexed: 08/10/2024]
Abstract
Prototyping analytical devices with three-dimensional (3D) printing techniques is becoming common in research laboratories. The attractiveness is associated with printers' price reduction and the possibility of creating customized objects that could form complete analytical systems. Even though 3D printing enables the rapid fabrication of electrochemical sensors, its wider adoption by research laboratories is hindered by the lack of reference material and the high "entry barrier" to the field, manifested by the need to learn how to use 3D design software and operate the printers. This review article provides insights into fused deposition modeling 3D printing, discussing key challenges in producing electrochemical sensors using currently available extrusion tools, which include desktop 3D printers and 3D printing pens. Further, we discuss the electrode processing steps, including designing, printing conditions, and post-treatment steps. Finally, this work shed some light on the current applications of such electrochemical devices that can be a reference material for new research involving 3D printing.
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Affiliation(s)
- Lauro A Pradela-Filho
- Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Diele A G Araújo
- Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Vanessa N Ataide
- Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Gabriel N Meloni
- Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Thiago R L C Paixão
- Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil.
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2
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Fernandes-Junior WS, Orzari LO, Kalinke C, Bonacin JA, Janegitz BC. A miniaturized additive-manufactured carbon black/PLA electrochemical sensor for pharmaceuticals detection. Talanta 2024; 275:126154. [PMID: 38703477 DOI: 10.1016/j.talanta.2024.126154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 04/22/2024] [Accepted: 04/24/2024] [Indexed: 05/06/2024]
Abstract
Additive manufacturing is a technique that allows the construction of prototypes and has evolved a lot in the last 20 years, innovating industrial fabrication processes in several areas. In chemistry, additive manufacturing has been used in several functionalities, such as microfluidic analytical devices, energy storage devices, and electrochemical sensors. Theophylline and paracetamol are important pharmaceutical drugs where overdosing can cause adverse effects, such as tachycardia, seizures, and even renal failure. Therefore, this paper aims at the development of miniaturized electrochemical sensors using 3D printing and polylactic acid-based conductive carbon black commercial filament for theophylline and paracetamol detection. Electrochemical characterizations of the proposed sensor were performed to prove the functionality of the device. Morphological characterizations were carried out, in which chemical treatment could change the surface structure, causing the improvement of the analytical signal. Thus, the detection of theophylline at a linear range of 5.00-150 μmol L-1 with a limit of detection of 1.2 μmol L-1 was attained, and the detection of paracetamol at a linear range of 1.00-200 μmol L-1 with a limit of detection of 0.370 μmol L-1 was obtained, demonstrating the proposed sensor effectively detected pharmaceutical drugs.
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Affiliation(s)
- Wilson S Fernandes-Junior
- Laboratory of Sensors, Nanomedicine, and Nanostructured Materials, Federal University of São Carlos, 13604-900, Araras, São Paulo, Brazil; Center for Sciences and Technology for Sustainability, Federal University of São Carlos, 18052-780, Sorocaba, São Paulo, Brazil
| | - Luiz O Orzari
- Laboratory of Sensors, Nanomedicine, and Nanostructured Materials, Federal University of São Carlos, 13604-900, Araras, São Paulo, Brazil; Center for Sciences and Technology for Sustainability, Federal University of São Carlos, 18052-780, Sorocaba, São Paulo, Brazil
| | - Cristiane Kalinke
- Institute of Chemistry, University of Campinas, 13083-970, Campinas, São Paulo, Brazil.
| | - Juliano A Bonacin
- Institute of Chemistry, University of Campinas, 13083-970, Campinas, São Paulo, Brazil
| | - Bruno C Janegitz
- Laboratory of Sensors, Nanomedicine, and Nanostructured Materials, Federal University of São Carlos, 13604-900, Araras, São Paulo, Brazil; Center for Sciences and Technology for Sustainability, Federal University of São Carlos, 18052-780, Sorocaba, São Paulo, Brazil.
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3
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de Moraes NC, Daakour RJB, Pedão ER, Ferreira VS, da Silva RAB, Petroni JM, Lucca BG. Electrochemical sensor based on 3D-printed substrate by masked stereolithography (MSLA): a new, cheap, robust and sustainable approach for simple production of analytical platforms. Mikrochim Acta 2023; 190:312. [PMID: 37470849 DOI: 10.1007/s00604-023-05912-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 07/11/2023] [Indexed: 07/21/2023]
Abstract
The development of miniaturized, sustainable and eco-friendly analytical sensors with low production cost is a current trend worldwide. Within this idea, this work presents the innovative use of masked stereolithography (MSLA) 3D-printed substrates for the easy fabrication of pencil-drawn electrochemical sensors (MSLA-3D-PDE). The use of a non-toxic material such as pencil (electrodes) together with a biodegradable 3D printing resin (substrate) allowed the production of devices that are quite cheap (ca. US$ 0.11 per sensor) and with low environmental impact. Compared to paper, which is the most used substrate for manufacturing pencil-drawn electrodes, the MSLA-3D-printed substrate has the advantages of not absorbing water (hydrophobicity) or becoming crinkled and weakened when in contact with solutions. These features provide more reproducible, reliable, stable, and long-lasting sensors. The MSLA-3D-PDE, in conjunction with the custom cell developed, showed excellent robustness and electrochemical performance similar to that observed of the glassy carbon electrode, without the need of any activation procedure. The analytical applicability of this platform was explored through the quantification of omeprazole in pharmaceuticals. A limit of detection (LOD) of 0.72 µmol L-1 was achieved, with a linear range of 10 to 200 µmol L-1. Analysis of real samples provided results that were highly concordant with those obtained by UV-Vis spectrophotometry (relative error ≤ 1.50%). In addition, the greenness of this approach was evaluated and confirmed by a quantitative methodology (Eco-Scale index). Thus, the MSLA-3D-PDE appears as a new and sustainable tool with great potential of use in analytical electrochemistry.
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Affiliation(s)
| | | | - Evandro Rodrigo Pedão
- Instituto de Análises Laboratoriais Forenses, Coordenadoria-Geral de Perícias de Mato Grosso do Sul, Campo Grande, MS, 79074-460, Brazil
| | - Valdir Souza Ferreira
- Chemistry Institute, Federal University of Mato Grosso do Sul, Campo Grande, MS, 79074-460, Brazil
| | | | | | - Bruno Gabriel Lucca
- Chemistry Institute, Federal University of Mato Grosso do Sul, Campo Grande, MS, 79074-460, Brazil.
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4
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Silva-Neto HA, Duarte-Junior GF, Rocha DS, Bedioui F, Varenne A, Coltro WKT. Recycling 3D Printed Residues for the Development of Disposable Paper-Based Electrochemical Sensors. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 36884339 DOI: 10.1021/acsami.3c00370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Here, we propose a recyclable approach using acrylonitrile-butadiene-styrene (ABS) residues from additive manufacturing in combination with low-cost and accessible graphite flakes as a novel and potential mixture for creating a conductive paste. The graphite particles were successfully incorporated in the recycled thermoplastic composite when solubilized with acetone and the mixture demonstrated greater adherence to different substrates, among which cellulose-based material made possible the construction of a paper-based electrochemical sensor (PES). The morphological, structural, and electrochemical characterizations of the recycled electrode material were demonstrated to be similar to those of the traditional carbon-based surfaces. Faradaic responses based on redox probe activity ([Fe(CN)6]3-/4-) exhibited well-defined peak currents and diffusional mass transfer as a quasi-reversible system (96 ± 5 mV) with a fast heterogeneous rate constant value of 2 × 10-3 cm s-1. To improve the electrode electrochemical properties, both the PES and the classical 3D-printed electrode surfaces were modified with a combination of multiwalled carbon nanotubes (MWCNTs), graphene oxide (GO), and copper. Both electrode surfaces demonstrated the suitable oxidation of nitrite at 0.6 and 0.5 V vs Ag, respectively. The calculated analytical sensitivities for PES and 3D-printed electrodes were 0.005 and 0.002 μA/(μmol L-1), respectively. The proposed PES was applied for the indirect amperometric analysis of S-nitroso-cysteine (CysNO) in serum samples via nitrite quantitation, demonstrating a limit of detection of 4.1 μmol L-1, with statistically similar values when compared to quantitative analysis of the same samples by spectrophotometry (paired t test, 95% confidence limit). The evaluated electroanalytical approach exhibited linear behavior for nitrite in the concentration range between 10 and 125 μmol L-1, which is suitable for realizing clinical diagnosis involving Parkinson's disease, for example. This proof of concept shows the great promise of this recyclable strategy combining ABS residues and conductive particles in the context of green chemical protocols for constructing disposable sensors.
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Affiliation(s)
- Habdias A Silva-Neto
- Instituto de Química, Universidade Federal de Goiás, 74690-900, Goiânia, GO Brazil
| | | | - Danielly S Rocha
- Instituto de Química, Universidade Federal de Goiás, 74690-900, Goiânia, GO Brazil
| | - Fethi Bedioui
- Institute of Chemistry for Life and Health Sciences i-CLeHS, Chimie ParisTech-PSL/CNRS, Paris 8060, France
| | - Anne Varenne
- Institute of Chemistry for Life and Health Sciences i-CLeHS, Chimie ParisTech-PSL/CNRS, Paris 8060, France
| | - Wendell K T Coltro
- Instituto de Química, Universidade Federal de Goiás, 74690-900, Goiânia, GO Brazil
- Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas 13084-971, São Paulo Brazil
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Kolitha BS, Jayasekara SK, Tannenbaum R, Jasiuk IM, Jayakody LN. Repurposing of waste PET by microbial biotransformation to functionalized materials for additive manufacturing. J Ind Microbiol Biotechnol 2023; 50:kuad010. [PMID: 37248049 PMCID: PMC10549213 DOI: 10.1093/jimb/kuad010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/20/2023] [Indexed: 05/31/2023]
Abstract
Plastic waste is an outstanding environmental thread. Poly(ethylene terephthalate) (PET) is one of the most abundantly produced single-use plastics worldwide, but its recycling rates are low. In parallel, additive manufacturing is a rapidly evolving technology with wide-ranging applications. Thus, there is a need for a broad spectrum of polymers to meet the demands of this growing industry and address post-use waste materials. This perspective article highlights the potential of designing microbial cell factories to upcycle PET into functionalized chemical building blocks for additive manufacturing. We present the leveraging of PET hydrolyzing enzymes and rewiring the bacterial C2 and aromatic catabolic pathways to obtain high-value chemicals and polymers. Since PET mechanical recycling back to original materials is cost-prohibitive, the biochemical technology is a viable alternative to upcycle PET into novel 3D printing materials, such as replacements for acrylonitrile butadiene styrene. The presented hybrid chemo-bio approaches potentially enable the manufacturing of environmentally friendly degradable or higher-value high-performance polymers and composites and their reuse for a circular economy. ONE-SENTENCE SUMMARY Biotransformation of waste PET to high-value platform chemicals for additive manufacturing.
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Affiliation(s)
- Bhagya S Kolitha
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL 62901, USA
| | - Sandhya K Jayasekara
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL 62901, USA
| | - Rina Tannenbaum
- Department of Materials Science and Chemical Engineering, the Stony Brook University Cancer Center, Stony Brook University, Stony Brook, NY 11794, USA
| | - Iwona M Jasiuk
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Lahiru N Jayakody
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL 62901, USA
- Fermentation Science Institute, Southern Illinois University Carbondale, Carbondale, IL 62901, USA
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6
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Paper-based electrochemical platform modified with graphene nanoribbons: A new and affordable approach for analysis of 5-hydroxy-l-tryptophan. Microchem J 2022. [DOI: 10.1016/j.microc.2022.108030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Stefano JS, Silva LRGE, Janegitz BC. New carbon black-based conductive filaments for the additive manufacture of improved electrochemical sensors by fused deposition modeling. Mikrochim Acta 2022; 189:414. [PMID: 36217039 PMCID: PMC9550156 DOI: 10.1007/s00604-022-05511-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/23/2022] [Indexed: 02/07/2023]
Abstract
The development of a homemade carbon black composite filament with polylactic acid (CB-PLA) is reported. Optimized filaments containing 28.5% wt. of carbon black were obtained and employed in the 3D printing of improved electrochemical sensors by fused deposition modeling (FDM) technique. The fabricated filaments were used to construct a simple electrochemical system, which was explored for detecting catechol and hydroquinone in water samples and detecting hydrogen peroxide in milk. The determination of catechol and hydroquinone was successfully performed by differential pulse voltammetry, presenting LOD values of 0.02 and 0.22 µmol L−1, respectively, and recovery values ranging from 91.1 to 112% in tap water. Furthermore, the modification of CB-PLA electrodes with Prussian blue allowed the non-enzymatic amperometric detection of hydrogen peroxide at 0.0 V (vs. carbon black reference electrode) in milk samples, with a linear range between 5.0 and 350.0 mol L−1 and low limit of detection (1.03 µmol L−1). Thus, CB-PLA can be successfully applied as additively manufactured electrochemical sensors, and the easy filament manufacturing process allows for its exploration in a diversity of applications.
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Affiliation(s)
- Jéssica Santos Stefano
- Department of Nature Sciences, Mathematics and Education, Federal University of São Carlos, Araras, São Paulo, 13600-970, Brazil
| | - Luiz Ricardo Guterres E Silva
- Department of Nature Sciences, Mathematics and Education, Federal University of São Carlos, Araras, São Paulo, 13600-970, Brazil.,Department of Physics, Chemistry, and Mathematics, Federal University of São Carlos, Sorocaba, São Paulo, 18052-780, Brazil
| | - Bruno Campos Janegitz
- Department of Nature Sciences, Mathematics and Education, Federal University of São Carlos, Araras, São Paulo, 13600-970, Brazil.
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de Oliveira FM, Mendonça MZM, de Moraes NC, Petroni JM, Neves MM, de Melo EI, Lucca BG, Bezerra da Silva RA. Exploring the coating of 3D-printed insulating substrates with conductive composites: a simple, cheap and versatile strategy to prepare customized high-performance electrochemical sensors. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 14:3345-3354. [PMID: 35979860 DOI: 10.1039/d2ay00803c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The development of 3D-printed electrochemical sensors by fused deposition modeling (FDM) has been increasing exponentially in the last five years. In this context, commercial conductive filaments composed of a blend of carbon particles (e.g., graphene or carbon black (CB)) and insulating thermoplastic polymers (e.g., polylactic acid (PLA) or acrylonitrile butadiene styrene (ABS)) have been widely used for electrode fabrication. However, such materials may be expensive and the electrodes when used "as-printed" exhibit poor electrochemical performance as a function of the low content of conductive particles in the composition (∼10 to 20 wt%), which requires one or more post-treatment steps (e.g. polishing, chemical, electrochemical, and photochemical) to reach good electrochemical performance. In this technical note a less used approach to produce "ready-to-use" electrochemical platforms based on 3D printing is explored, which consists of the coating of 3D-printed insulating substrates with homemade conductive composites. To demonstrate the potentiality of this alternative protocol, 3D-printed ABS insulating substrates at two geometries were coated in a highly loaded graphite (55 wt%) homemade composite (G-ABS) and evaluated for the detection of the ferri/ferrocyanide redox probe and model analytes in stationary and hydrodynamic 3D-printed systems (nitrite in micro-flow injection analysis/μFIA and paracetamol in batch injection analysis/BIA, respectively). The analytical parameters acquired with the coated electrodes were comparable to those obtained using conventional electrodes (glassy carbon, boron-doped diamond and carbon screen-printed) and 3D-printed sensors fabricated with commercial filaments. Moreover, the inclusion of carbon black in the fluid conductive composite was demonstrated as a perspective to obtain modified coated 3D-printed surfaces easily for the first time. This alternative "do it yourself" strategy is promising for the large-scale production of very cheap (US$ 0.08) and high-performance electrodes based on FDM 3D printing. Moreover, this approach dispenses the acquisition of commercial conductive filaments and the laborious development of homemade filaments.
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Affiliation(s)
| | | | | | | | - Matheus Meneguel Neves
- Chemistry Institute, Federal University of Mato Grosso Do Sul, Campo Grande, MS, 79074-460, Brazil
| | - Edmar Isaias de Melo
- Chemistry Institute, Federal University of Uberlândia, Monte Carmelo, MG, 38500-000, Brazil.
| | - Bruno Gabriel Lucca
- Chemistry Institute, Federal University of Mato Grosso Do Sul, Campo Grande, MS, 79074-460, Brazil
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Stefano JS, Kalinke C, da Rocha RG, Rocha DP, da Silva VAOP, Bonacin JA, Angnes L, Richter EM, Janegitz BC, Muñoz RAA. Electrochemical (Bio)Sensors Enabled by Fused Deposition Modeling-Based 3D Printing: A Guide to Selecting Designs, Printing Parameters, and Post-Treatment Protocols. Anal Chem 2022; 94:6417-6429. [PMID: 35348329 DOI: 10.1021/acs.analchem.1c05523] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The 3D printing (or additive manufacturing, AM) technology is capable to provide a quick and easy production of objects with freedom of design, reducing waste generation. Among the AM techniques, fused deposition modeling (FDM) has been highlighted due to its affordability, scalability, and possibility of processing an extensive range of materials (thermoplastics, composites, biobased materials, etc.). The possibility of obtaining electrochemical cells, arrays, pieces, and more recently, electrodes, exactly according to the demand, in varied shapes and sizes, and employing the desired materials has made from 3D printing technology an indispensable tool in electroanalysis. In this regard, the obtention of an FDM 3D printer has great advantages for electroanalytical laboratories, and its use is relatively simple. Some care has to be taken to aid the user to take advantage of the great potential of this technology, avoiding problems such as solution leakages, very common in 3D printed cells, providing well-sealed objects, with high quality. In this sense, herein, we present a complete protocol regarding the use of FDM 3D printers for the fabrication of complete electrochemical systems, including (bio)sensors, and how to improve the quality of the obtained systems. A guide from the initial printing stages, regarding the design and structure obtention, to the final application, including the improvement of obtained 3D printed electrodes for different purposes, is provided here. Thus, this protocol can provide great perspectives and alternatives for 3D printing in electroanalysis and aid the user to understand and solve several problems with the use of this technology in this field.
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Affiliation(s)
- Jéssica Santos Stefano
- Department of Nature Sciences, Mathematics and Education, Federal University of São Carlos, 13600-970, Araras, São Paulo, Brazil
| | - Cristiane Kalinke
- Institute of Chemistry, University of Campinas, 13083-859, Campinas, São Paulo, Brazil
| | - Raquel Gomes da Rocha
- Institute of Chemistry, Federal University of Uberlândia, 38400-902, Uberlândia, Minas Gerais, Brazil
| | - Diego Pessoa Rocha
- Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, 05508-000, São Paulo, São Paulo, Brazil.,Department of Chemistry, Federal Institute of Paraná, 85200-000, Pitanga, Paraná, Brazil
| | | | - Juliano Alves Bonacin
- Institute of Chemistry, University of Campinas, 13083-859, Campinas, São Paulo, Brazil
| | - Lúcio Angnes
- Institute of Chemistry, Department of Fundamental Chemistry, University of São Paulo, 05508-000, São Paulo, São Paulo, Brazil
| | - Eduardo Mathias Richter
- Institute of Chemistry, Federal University of Uberlândia, 38400-902, Uberlândia, Minas Gerais, Brazil
| | - Bruno Campos Janegitz
- Department of Nature Sciences, Mathematics and Education, Federal University of São Carlos, 13600-970, Araras, São Paulo, Brazil
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Simple, fast, and instrumentless fabrication of paper analytical devices by novel contact stamping method based on acrylic varnish and 3D printing. Mikrochim Acta 2021; 188:437. [PMID: 34837526 DOI: 10.1007/s00604-021-05102-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/11/2021] [Indexed: 12/27/2022]
Abstract
A new contact stamping method for fabrication of paper-based analytical devices (PADs) is reported. It uses an all-purpose acrylic varnish and 3D-printed stamps to pattern hydrophobic structures on paper substrates. The use of 3D printing allows quickly prototyping the desired stamp shape without resorting to third-party services, which are often expensive and time consuming. To the best of our knowledge, this is the first report regarding the use of this material for creation of hydrophobic barriers in paper substrates, as well as this 3D printing-based stamping method. The acrylic varnish was characterized and the features of the stamping method were studied. The PADs developed here presented better compatibility with organic solvents and surfactants compared with similar protocols. Furthermore, the use of this contact stamping method for fabrication of paper electrochemical devices was also possible, as well as multiplexed microfluidic devices for lateral flow testing. The analytical applicability of the varnish-based PADs was demonstrated through the image-based colorimetric quantification of iron in pharmaceutical samples. A limit of detection of 0.61 mg L-1 was achieved. The results were compared with spectrophotometry for validation and presented great concordance (relative error was < 5% and recoveries were between 104 and 108%). Thus, taking into account the performance of the devices explored here, we believe this novel contact stamping method is a very interesting alternative for production of PADs, exhibiting great potentiality. In addition, this work brings a new application of 3D printing in analytical sciences.
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