Design and Characterization of Effective Ag, Pt and AgPt Nanoparticles to H₂O₂ Electrosensing from Scrapped Printed Electrodes.

Beatriz Gómez-Monedero,Jesús Iniesta,Edelmira Valero,María-Isabel González-Sánchez,Jerónimo Agrisuelas

doi:10.3390/s19071685

Abstract

The use of disposable screen-printed electrodes (SPEs) has extraordinarily grown in the last years. In this paper, conductive inks from scrapped SPEs were removed by acid leaching, providing high value feedstocks suitable for the electrochemical deposition of Ag, Pt and Ag core-Pt shell-like bimetallic (AgPt) nanoparticles, onto screen-printed carbon electrodes (ML@SPCEs, M = Ag, Pt or AgPt, L = metal nanoparticles from leaching solutions). ML@SPCEs were characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results were compared to those obtained when metal nanoparticles were synthesised using standard solutions of metal salts (MS@SPCEs). Both ML@SPCEs and MS@SPCEs exhibited similar cyclic voltammetric patterns referred to the electrochemical stripping of silver or the adsorption/desorption of hydrogen/anions in the case of platinum, proving leaching solutions extremely effective for the electrodeposition of metallic nanoparticles. The use of both ML@SPCEs and MS@SPCEs proved effective in enhancing the sensitivity for the detection of H2O2 in phosphate buffer solutions (pH = 7). The AgPtL@SPCE was used as proof of concept for the validation of an amperometric sensor for the determination of H2O2 within laundry boosters and antiseptic samples. The electrochemical sensor gave good agreement with the results obtained by a spectrophotometric method with H2O2 recoveries between 100.6% and 106.4%.

Highlights

Screen-printed electrodes (SPEs) are conductive inks printed onto a ceramic or plastic sheet to manufacture a small, disposable electrochemical cell at relatively low cost
Prior to the screen-printed platinum electrodes (SPPtEs) leachate treatment, Ag and Pt conductive inks were explored by SEM and energy dispersive X-ray analysis (EDS)
Was attributed to the electroreduction of Ag+ to Ag0 according to Equation (1), while the second cathodic peak at −0.60 V was associated to the electroreduction of the electrolyte, as being proved by the linear sweep voltammetries (LSVs) experiments performed in the absence of Ag+ in solution

Summary

Introduction

Screen-printed electrodes (SPEs) are conductive inks printed onto a ceramic or plastic sheet to manufacture a small, disposable electrochemical cell at relatively low cost. Such inks are based on different conductive loadings, like silver, platinum, gold, graphite or conducting polymers, which allow the production of electrochemical devices with many advantages compared to classical working electrodes. Due to the benefits of cost-effectiveness or suitability for working with microvolumes of sample, among numerous others [1,2], SPEs have experienced a growing use in numerous analytical applications, as in the biomedical [3], pharmaceutical [4], food [5], industrial [6], teaching [7,8] and environmental sectors [9,10]. In view of the growth that the use of SPEs has undergone in the last 20 years (Figure S1 in the Supplementary Material), their efficient use and feasible recycling are of utmost importance [13]

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Conclusion