title: Pencil It in: Exploring the Feasibility of Hand-Drawn Pencil Electrochemical Sensors and Their Direct Comparison to Screen-Printed Electrodes.
abstract: We explore the fabrication, physicochemical characterisation (SEM, Raman, EDX and XPS) and electrochemical application of hand-drawn pencil electrodes (PDEs) upon an ultra-flexible polyester substrate; investigating the number of draws (used for their fabrication), the pencil grade utilised (HB to 9B) and the electrochemical properties of an array of batches (i.e, pencil boxes). Electrochemical characterisation of the PDEs, using different batches of HB grade pencils, is undertaken using several inner- and outer-sphere redox probes and is critically compared to screen-printed electrodes (SPEs). Proof-of-concept is demonstrated for the electrochemical sensing of dopamine and acetaminophen using PDEs, which are found to exhibit competitive limits of detection (3σ) upon comparison to SPEs. Nonetheless, it is important to note that a clear lack of reproducibility was demonstrated when utilising these PDEs fabricated using the HB pencils from different batches. We also explore the suitability and feasibility of a pencil-drawn reference electrode compared to screen-printed alternatives, to see if one can draw the entire sensing platform. This article reports a critical assessment of these PDEs against that of its screen-printed competitors, questioning the overall feasibility of PDEs' implementation as a sensing platform.
authors: Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK. ebernaltemorgado@gmail.com.|Departamento de Química Analítica e IACYS, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s/n, 06006 Badajoz, Spain. ebernaltemorgado@gmail.com.
authors: Elena
authors: E
authors: Bernalte
authors: Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK. chris.w.foster@mmu.ac.uk.
authors: Christopher W
authors: CW
authors: Foster
authors: Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK. d.brownson@mmu.ac.uk.
authors: Dale A C
authors: DA
authors: Brownson
authors: Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK. morgane.mosna@etu.iut-tlse3.fr.
authors: Morgane
authors: M
authors: Mosna
authors: Faculty of Science and Engineering, Department of Natural Sciences, University of Chester, Thorntorn Science Park, Pool Lane, Ince, Manchester CH2 4NU, UK. graham.smith@chester.ac.uk.
authors: Graham C
authors: GC
authors: Smith
authors: Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK. c.banks@mmu.ac.uk.
authors: Craig E
authors: CE
authors: Banks
mesh_terms: D000082:Acetaminophen / Q000737:chemistry; D015374:Biosensing Techniques; D004298:Dopamine / Q000737:chemistry; D055664:Electrochemical Techniques; D004563:Electrochemistry; D004566:Electrodes; D015203:Reproducibility of Results
chemical_list: D000082:Acetaminophen; D004298:Dopamine
keywords: electrochemistry; pencil-drawn electrodes; screen-printed electrodes; sensors