Xurography-Enabled Thermally Transferred Carbon Nanomaterial-Based Electrochemical Sensors on Polyethylene Terephthalate–Ethylene Vinyl Acetate Films

Abstract

A novel benchtop approach to fabricate xurography-enabled thermally transferred (XTT) carbon nanomaterial-based electrochemical sensors is proposed. Filtered nanomaterial (NM) films were transferred from Teflon filters to polyethylene terephthalate–ethylene vinyl acetate (PET-EVA) substrates by a temperature-driven approach. Customized PET-EVA components were xurographically patterned by a cutting plotter. The smart design of PET-EVA films enabled us to selectively transfer the nanomaterial to the exposed EVA side of the substrate. Hence, the substrate played an active role in selectively controlling where nanomaterial transfer occurred allowing us to design different working electrode geometries. Counter and reference electrodes were integrated by a stencil-printing approach, and the whole device was assembled by thermal lamination. To prove the versatility of the technology, XTT materials were exclusively made of carbon black (XTT-CB), multiwalled carbon nanotubes (XTT-MWCNTs), and single-walled carbon nanotubes (XTT-SWCNTs). Their electrochemical behavior was carefully studied and was found to be highly dependent on the amount and type of NM employed. XTT-SWCNTs were demonstrated to be the best-performing sensors, and they were employed for the determination of l-tyrosine (l-Tyr) in human plasma from tyrosinemia-diagnosed patients. High analytical performance toward l-Tyr (linear range of 0.5–100 μM, LOD = 0.1 μM), interelectrode precision (RSD i p,a = 3%, n = 10; RSD calibration slope = 4%, n = 3), and accurate l-Tyr quantification in plasma samples with low relative errors (≤7%) compared to the clinical declared values were obtained. The proposed benchtop approach is cost-effective and straightforward, does not require sophisticated facilities, and can be potentially employed to develop pure or hybrid nanomaterial-based electrodes.

Water-Phase Exfoliated Biochar Nanofibers from Eucalyptus Scraps for Electrode Modification and Conductive Film Fabrication

“…Films based exclusively on nanomaterials and their integration into flexible plastic and paper substrates to fabricate cutting-edge sensors and devices represent a hot research topic . In this regard, graphene and graphene-like materials, carbon black, , and carbon nanotubes have been extensively studied, while fully biochar-based films for electroanalytical purposes are not yet exploited. Probably, this lack can be attributed to heterogeneous structures of biochar.…”

“…Recently, miniaturized electrochemical platforms move toward low-impact materials (cellulose, polylactic acid, recyclable flexible plastics, etc.) and affordable lab-attainable manufacturing technologies. ,, In this regard, biochar may represent potentially the “gold material”, considering the sustainability, versatility, and effectiveness. Biochar integration onto innovative “supports” represents a new compelling research field in environmental remediation and also in material science, wherein particular biochar nanofibers are used to construct electrospun, electrospun-based polymers, and modified textiles .…”

Carbon Black Functionalized with Naturally Occurring Compounds in Water Phase for Electrochemical Sensing of Antioxidant Compounds

“…Among the different commercially available CBs, an interesting study by Mazzaracchio et al [ 5 ] demonstrated the superior electron transfer ability of the N220 type. For this reason, this type of CB has been largely employed for electrochemical sensor/device implementation using different approaches: electrode modification via drop casting [ 7 , 8 , 9 , 10 , 11 ], fabrication of transducers via press/thermal transfer [ 12 , 13 , 14 , 15 ], or CB inclusion in conductive inks/pastes [ 16 , 17 ]. The classical strategy to prepare/disperse CB for electroanalytical purposes relies on its dispersion in organic solvents.…”

Versatile and Easily Designable Polyester-Laser Toner Interfaces for Site-Oriented Adsorption of Antibodies

“…So far, laser toner has found applications, i.a., as a hydrophobic barrier for valves and droplet handling [ 25 , 26 ] and a material for formation of microstructures, as well as a thermo-responsive adhesive that enables lamination [ 27 , 28 ]. A number of microfluidic analytical systems using PET-toner interfaces have been developed for applications such as capillary electrophoresis [ 29 ], separation of nucleic acids [ 30 , 31 ], and chemical and biochemical assays (using colorimetric or enzymatic reactions) for the determination of relevant analytes [ 32 , 33 , 34 , 35 ]. Until now, laser toner has not been considered in a construction of immunoassays as a readily applied, hydrophobic substrate for the direct, passive immobilization of antibodies.…”