Integration of Commercial Screen‐printed Electrodes into a Voltammetric Electronic Tongue for the Analysis of Aminothiols

Abstract

A voltammetric sensor array (or electronic tongue) is developed for the simultaneous quantification of cysteine, glutathione and homocysteine without need of previous separation. It is based on the integration of three commercial screen‐printed electrodes (gold curated at high and low temperature and carbon modified with carbon nanotubes). Linear sweep voltammograms measured simultaneously by all three sensors are processed by Partial Least Squares (PLS) regression and different variables selection algorithms such as Genetic Algorithm and interval‐Partial Least Squares. The method was applied to synthetic mixtures and successfully validated, with correlation coefficients of prediction (Rp2) of 0.9542, 0.9429 and 0.9589 for cysteine, glutathione, and homocysteine respectively.

A Voltammetric Electronic Tongue Based on Commercial Screen‐printed Electrodes for the Analysis of Aminothiols by Differential Pulse Voltammetry

“…A preliminary study was made to stablish a convenient working pH for several commercially available screen‐printed electrodes that, according to previous results, could be good candidates to constitute an improved voltammetric electronic tongue. These are the low‐temperature and high‐temperature cured gold electrodes (AuBT and AuAT, respectively) successfully used in , the carbon nanofibers electrode (CNF), a device with similar or even better features than carbon nanotubes , and the simple, cheap and versatile carbon electrode.…”

“…In a similar way, the tests made with different electrodes and analytes suggested that a pH value of 7.4 (obtained with tris buffer) would be a good compromise to obtain an optimal performance of the electrodes when they work together in the same solution. It should be pointed out that, in contrast to the acidic medium used in the previous tongue or the chromatographic method , this optimal pH of 7.4 is really close to biological conditions.…”

“…In contrast, AuAT, produces voltammograms with small and poorly reproducible variations at increasing concentrations of the aminothiols considered at pH 7.4. Thus, although it had been suitable in studies carried out at acidic pH ,, AuAT electrode was discarded in the present work, developed at slightly basic pH.…”

“…Recently, a voltammetric electronic tongue was designed by our research group as a proof of concept for the analysis of Cys, hCys and GSH . It consisted of two commercial SPE made of gold cured at high and low temperature and a third one home‐made modified with carbon nanotubes.…”

Artificial neural networks (ANNS) versus partial least squares (PLS) for spectral interference correction for taking part of the lab to the sample types of applications: an experimental study

“…In the last few years, PLS has been described in books and in tutorials [25][26][27][28][29][30][31][32]. Currently, PLS is receiving increased attention in the literature, for instance, during the last year or so, several papers describing the application of PLS to chemical problems have been published [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49].…”