Analytical sensing platforms with inkjet printed electrodes (original) (raw)

Large scale inkjet-printing of carbon nanotubes electrodes for antioxidant assays in blood bags

Journal of Electroanalytical Chemistry, 2014

Herein, we present the large scale fabrication of carbon nanotubes (CNT) electrodes supported on flexible polymeric sheets by subsequent multilayer inkjet printing of a silver layer for electrical connection, CNT layers as active electrode material and an insulation layer to define a stand-alone CNT active electrode area with high accuracy. Optical and electrochemical characterization using several redox mediators demonstrates the reproducibility of the electrode surfaces and their functionality even with a single inkjet printed CNT layer. These electrodes are targeted to the clinical sector for the determination of the antioxidant power (AOP) of biologically relevant fluids by pseudo-titration voltammetry. As a proof-ofconcept, the AOP of ascorbic acid solutions and biological samples such as erythrocyte concentrates (ECs) from different blood donors were determined demonstrating the potential use of the presented CNT sensors on ECs for blood transfusion purposes and the clinical sector.

Silver Inkjet-Printed Electrode on Paper for Electrochemical Sensing of Paraquat

2021

The use of fully printed electrochemical devices has gained more attention for the monitoring of clinical, food, and environmental analytes due to their low cost, great reproducibility, and versatility characteristics, serving as an important technology for commercial application. Therefore, a paper-based inkjet-printed electrochemical system is proposed as a cost-effective analytical detection tool for paraquat. Chromatographic paper was used as the printing substrate due its sustainable and disposable characteristics, and an inkjet-printing system deposited the conductive silver ink with no further modification on the paper surface, providing a three-electrode system. The printed electrodes were characterized with scanning electron microscopy, cyclic voltammetry, and chronopotentiometry. The proposed sensor exhibited a large surface area, providing a powerful tool for paraquat detection due to its higher analytical signal. For the detection of paraquat, square-wave voltammetry was used, and the results showed a linear response range of 3.0–100 µM and a detection limit of 0.80 µM, along with the high repeatability and disposability of the sensor. The prepared sensors were also sufficiently selective against interference, and high accuracy (recovery range = 96.7–113%) was obtained when applied to samples (water, human serum, and orange juice), showing the promising applicability of fully printed electrodes for electrochemical monitoring. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY)

A low-cost paper-based inkjet-printed platform for electrochemical analyses

Sensors and Actuators B: Chemical, 2013

An electrode platform printed on a recyclable low-cost paper substrate was characterized using cyclic voltammetry. The working and counter electrodes were directly printed gold-stripes, while the reference electrode was a printed silver stripe onto which an AgCl layer was deposited electrochemically. The novel paper-based chips showed comparable performance to conventional electrochemical cells. Different types of electrode modifications were carried out to demonstrate that the printed electrodes behave similarly with conventional electrodes. Firstly, a self-assembled monolayer (SAM) of alkanethiols was successfully formed on the Au electrode surface. As a consequence, the peak currents were suppressed and no longer showed clear increase as a function of the scan rate. Such modified electrodes have potential in various sensor applications when terminally substituted thiols are used. Secondly, a polyaniline film was electropolymerized on the working electrode by cyclic voltammetry and used for potentiometric pH sensing. The calibration curve showed close to Nerstian response. Thirdly, a poly(3,4-ethylenedioxythiophene) (PEDOT) layer was electropolymerized both by galvanostatic and cyclic potential sweep method on the working electrode using two different dopants; Cl − to study ionto-electron transduction on paper-Au/PEDOT system and glucose oxidase in order to fabricate a glucose biosensor. The planar paper-based electrochemical cell is a user-friendly platform that functions with low sample volume and allows the sample to be applied and changed by e.g. pipetting. Low unit cost is achieved with mask-and mesh-free inkjet-printing technology.

Inkjet Printed Nanohydrogel Coated Carbon Nanotubes Electrodes For Matrix Independent Sensing

Analytical Chemistry, 2015

Polyacrylamide (PA) based hydrogels are used in several applications including polyacrylamide gel electrophoresis and sensing devices. Homogeneous and compact PA films can be prepared based on chemical or photopolymerization processes. However, the accurate and reproducible coating of substrates with nanohydrogel patterns is challenging due to the in situ polymerization and deposition requirements. Herein, we report an inkjet printing (IJP) concept with simultaneously performed UV photopolymerization of a specifically prepared acrylamide/N,N′-methylenebis(acrylamide) containing ink. A prepolymerization step of the hydrogel precursor molecules was implemented in the ink formulation protocol to adjust the viscosity of the ink and to enhance the rate of polymerization during printing. After the optimization of the printing parameters, a nanometer thin PA hydrogel coating with well distributed nanopores was achieved on top of a stand-alone carbon nanotubes (CNTs) pattern. Batches of fully inkjet printed PA/CNT modified electrodes were prepared that showed outstanding improvements for the electrochemical detection of antioxidants in complex matrices such as untreated orange juice and red wine samples thanks to the properties of the PA coating.

Biosensing with Paper-Based Miniaturized Printed Electrodes-A Modern Trend

Biosensors, 2016

From the bench-mark work on microfluidics from the Whitesides's group in 2007, paper technology has experienced significant growth, particularly regarding applications in biomedical research and clinical diagnostics. Besides the structural properties supporting microfluidics, other advantageous features of paper materials, including their versatility, disposability and low cost, show off the great potential for the development of advanced and eco-friendly analytical tools. Consequently, paper was quickly employed in the field of electrochemical sensors, being an ideal material for producing custom, tailored and miniaturized devices. Stencil-, inkjet-, or screen-printing are the preferential techniques for electrode manufacturing. Not surprisingly, we witnessed a rapid increase in the number of publications on paper based screen-printed sensors at the turn of the past decade. Among the sensing strategies, various biosensors, coupling electrochemical detectors with biomolecules, h...

Fully Inkjet-Printed Biosensors Fabricated with a Highly Stable Ink Based on Carbon Nanotubes and Enzyme-Functionalized Nanoparticles

Nanomaterials

Enzyme inks can be inkjet printed to fabricate enzymatic biosensors. However, inks containing enzymes present a low shelf life because enzymes in suspension rapidly lose their catalytic activity. Other major problems of printing these inks are the non-specific adsorption of enzymes onto the chamber walls and stability loss during printing as a result of thermal and/or mechanical stress. It is well known that the catalytic activity can be preserved for significantly longer periods of time and to harsher operational conditions when enzymes are immobilized onto adequate surfaces. Therefore, in this work, horseradish peroxidase was covalently immobilized onto silica nanoparticles. Then, the nanoparticles were mixed into an aqueous ink containing single walled carbon nanotubes. Electrodes printed with this specially formulated ink were characterized, and enzyme electrodes were printed. To test the performance of the enzyme electrodes, a complete amperometric hydrogen peroxide biosensor w...

Ultra stable, inkjet-printed pseudo reference electrodes for lab-on-chip integrated electrochemical biosensors

Scientific Reports

Lab-on-Chip technology comprises one of the most promising technologies enabling the widespread adoption of Point-of-Care testing in routine clinical practice. However, until now advances in Lab-on-Chip have not been translated to the anticipated degree to commercialized tools, with integrated device mass manufacturing cost still not at a competitive level for several key clinical applications. Lab-on-PCB is currently considered as a candidate technology addressing this issue, owing to its intuitive compatibility with electronics, seamless integration of electrochemical biosensors and the extensive experience regarding industrial manufacturing processes. Inkjet-printing in particular is a compatible fabrication method, widening the range of electronic materials available and thus enabling seamlessly integrated ultrasensitive electronic detection. To this end, in this work stable pseudo-reference electrodes are fabricated for the first time by means of commercial inkjet-printing on a...

All-inkjet-printed dissolved oxygen sensors on flexible plastic substrates

Organic Electronics, 2016

Inkjet printing is a promising alternative manufacturing method to conventional standard microfabrication techniques for the development of flexible and low-cost devices. Although the use of inkjet printing for the deposition of selected materials for the development of sensor devices has been reported many times in literature, it is still a challenge and a potential route towards commercialization to completely manufacture sensor devices with inkjet technology. In this work is demonstrated the fabrication of a functional low-cost dissolved oxygen (DO) amperometric sensor with feature sizes in the micrometer range using inkjet printing. All the required technological steps for the fabrication of a complete electrochemical three electrodes system are discussed in detail. The working and counter electrodes have been printed using a gold nanoparticle ink, whereas a silver nanoparticle ink was used to print a pseudo-reference electrode. Both inks are commercially available and can be sintered at low temperatures, starting already at 120 C, which allows the use of plastic substrates. In addition, a printable SU8 ink formulation cured by UV is applied as passivation layer in the sensor device. Finally, as the performance of analytical methods strongly depends on the working electrode material, is demonstrated the electrochemical feasibility of this printed DO sensor, which shows a linear response in the range between 0 and 8 mg L À1 of DO, and affords a detection limit of 0.11 mg L À1 , and a sensitivity of 0.03 mA L mg À1. The use of flexible plastic substrates and biocompatible inks, and the rapid prototyping and low-cost of the fabricated sensors, makes that the proposed manufacturing approach opens new opportunities in the field of biological and medical sensor applications.

Printed Paper–Based Electrochemical Sensors for Low-Cost Point-of-Need Applications

Electrocatalysis, 2019

Paper-based microfluidics is a rapidly developing field with applications for point-of-care disease and environmental diagnostics. In parallel, printed electronics has grown swiftly, particularly for wearable technologies. By combining these fields, fluidic sample processing and control, as well as automated sensing and readout can be integrated on a single device. Towards this goal, this work highlights the design, manufacture, and testing of paper-based electrochemical sensors, with focus on photo paper and chromatography paper substrates. These substrates are typically used for printed electronics and paper-based fluidics, respectively. The electrochemical sensors were screen printed using manual techniques. For chromatography paper sensors, wax-printed fluidic barriers were used to illustrate the potential integration of the sensors with typical paper-based microfluidic device formats. As an initial example, the detection of heavy metals (Cd(II) and Pb(II)) in buffer solution was demonstrated. Commercial DropSens sensors were used as reference with the limit of detection (LOD) of Cd(II) and Pb(II) on chromatography sensors showing comparable results to commercial DropSens sensors. It is worth noting that the chromatography paper sensors showed a higher repeatability than the commercial DropSens sensors. Tap water samples spiked with Cd(II) and Pb(II) were also tested and showed promising results. Future work will include sensor optimization and exploration of scale-up to provide lowcost solutions for effective point-of-need diagnostics-ranging from environmental monitoring to healthcare applications.

Inkjet printing of chemiresistive sensors based on polymer and carbon nanotube networks

International Multi-Conference on Systems, Sygnals & Devices, 2012

We report about the manufacturing of sensor devices for detection of volatile organic compounds (VOCs) in the air. The sensor comprises three fully inkjet-printed layers of (i) silver interdigitated electrodes (SIDE), (ii) multi-walled carbon nanotubes (MWCNTs) and (iii) poly (styrene-co-maleic acid) partial isobutyl/methyl mixed ester (PSE). We have found that inkjet printing of MWCNT layers and a PSE layer on top yields an interfacial layer leading to the formation of a MWCNTs/PSE composite-like structure. The printed layers act as chemiresistive vapor sensors due to the change of electrical resistance in presence of selected VOCs. The sensor responses to various VOCs were studied by varying the concentration of the chemicals in the air between 50 and 500 ppm. The sensing mechanism can be understood as a fractional volume change of the inkjet-printed polymer that occurs during exposure to VOCs, resulting in a structural alteration of the MWCNT-polymer network. We have found that the sensor response can be defined as a function of the VOC's concentration. To investigate the morphologies of the inkjet-printed thin films, profilometry and scanning electron microscopy (SEM) were employed.