Adil Ait Yazza, Pascal Blondeau, Francisco J. Andrade
ACS Applied Electronic Materials
Organic electrochemical transistors (OECTs) have attracted great interest in the last few years as biochemical sensors due to their outstanding analytical performance, versatility, stability, and easiness of fabrication. While thin-film OECTs have been studied extensively, their manufacturing still presents some challenges. This report presents a simple approach for developing OECT using a paper substrate and a thick-film approach that shows outstanding performance. The channel is hand-made by dip pen deposition of the conducting polymer poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS). This allows reproducible channel thickness in the order of 6 μm, well above the conventionally used values. This device displays a high transconductance that exceeds 40 mS and an on-to-off current ratio of 3.8 × 10³ comparable or superior to the state-of-the-art paper-based OECTs. The advantages of this approach are illustrated with the detection of H2O2 and glucose, obtaining sensitivities above 1.5 mA/dec. This simplified approach and high sensitivity may help to extend the use of the OECT-based sensors, particularly in the distributed and point-of need applications.
Borràs-Brull, M., Blondeau, P., Riu, J.
Critical Reviews in Analytical Chemistry 2020, in press. Doi: 10.1080/10408347.2020.1718482
Cánovas, R., Blondeau, P., Andrade, F.J.
Biosensors and Bioelectronics 2020, 163 article number 112302. Doi: 10.1016/j.bios.2020.112302
This work presents a novel strategy to control the mixed potential that allows the development of a potentiometric biosensor for the direct detection of glucose in whole, undiluted blood without any sample pretreatment. The accurate measurement of blood sugar levels in a single drop of whole blood with excellent recovery is presented.
Mohamed Bouri, Julio C. Zuaznabar-Gardona, Marta Novell, Pascal Blondeau, Francisco J. Andrade
Electroanalysis 2020, doi: 10.1002/elan.202060285
A filter paper sputtered with a layer of Pt and subsequently coated with a Nafion® membrane is used as working electrode. The mixed potential of the Pt electrode allows the detection of H2O2 generated by the oxidation of galactose in the presence of the galactose oxidase enzyme. This provides a simple and mediator‐free approach method. The system shows sensitivity values of −62.8±9.4 mV/decade of galactose in the range from 0.3 to 31.6 mM, well within the clinical relevant range. MnO2 nanoparticles were added to decrease the interference from ascorbic acid so that validation of the sensor in whole blood samples was performed with good recovery.
Jhonattan F. Baez, Matthew Compton, Sylviane Chahrati, Rocío Cánovas, Pascal Blondeau, Francisco J. Andrade
Analytica Chimica Acta 2020, 1097(8) 204-213, doi: 10.1016/j.aca.2019.11.018
The use of a Pt electrode coated with a layer of Nafion has been described in previous works as an attractive way to perform the potentiometric detection of hydrogen peroxide. Despite the attractive features of this approach, the nature of the non-Nernstian response of this system was not properly addressed. This work provides a phenomenological view of the problem. A general framework to understand the factors that affect the potentiometric response is provided. Experimental evidence showing that the use of polyelectrolyte coatings are a powerful way to control the mixed potential open new ways for the development of robust and simple potentiometric sensors.
Marta Novell, Nayra Rico, Pascal Blondeau, Miquel Blasco, Adrià Maceira, José Luis Bedini, Francisco Javier Andrade, Francesc Maduell
Letter to the editor in Nefrología, doi: 10.1016/j.nefro.2019.06.002
Determination of potassium levels in serum is routinely performed in clinical labs, as it is a critical parameter and abnormal potassium concentrations may lead to fatal cardiac consequences. An immediate test for determination of blood potassium may contribute to prevent such critical issues, for example, arrhythmias. Therefore we have developed and tested a novel point-of-care (POC) device that provides a simple and highly affordable way of measuring potassium levels in a single drop of blood outside the clinical laboratory. This POC device has demonstrated a good correlation with the reference method, proving that it can be an alternative for specific situations where an immediate response is required.
Miguel M. Erenas, Inmaculada Ortiz-Gómez, Ignacio de Orbe-Payá, Daniel Hernández-Alonso, Pablo Ballester, Pascal Blondeau, Francisco J. Andrade, Alfonso Salinas-Castillo, and Luis Fermín Capitán-Vallvey
ACS Sensors 2019, 4, 421-426
An optical disposable sensor for monitoring creatinine levels in urine is described in this paper. The new sensor displays a good response time to creatinine (approximately 3 min) over a wide dynamic range (from 1 × 10−5 to 1 × 10−2 M). Moreover, the optical selectivity coefficients obtained for creatinine over common cations present in urine meet the requirements for real sample measurements, providing a simple, quick, cost-effective, and selective alternative to the conventional methodology based on Jaffe’s reaction.
Rafael Hoekstra, Pascal Blondeau, Francisco J. Andrade
Analytical and Bioanalytical Chemistry 2018, 410, 4077-4089
We present a brief survey of key challenges and advances in the development of distributed electrochemical sensors for liquid samples, geared towards applications in healthcare and wellbeing, environmental monitoring, and homeland security.
Rafael Hoekstra, Pascal Blondeau, Francisco J. Andrade
Electroanalysis, 2018, 30, 1536-1544
A sensor for monitoring total ion activity is described, and its performance as a wearable device for monitoring the total ion levels of sweat is evaluated. The excellent reproducibility of the electrode without any conditioning is noteworthy.
Leonor Guadarrama-Fernández, Marta Novell, Pascal Blondeau, Francisco J.Andrade
Food Chemistry 2018, 265, 64-69
A new biosensor for monitoring glucose levels in beverages is presented. The methodology presented herein does not require complex samples treatment, offering an alternative to conventional methods, particularly for determinations performed with minimal expertise and without a laboratory infrastructure.