title: WO3 nanoparticle-based conformable pH sensor.
abstract: pH is a vital physiological parameter that can be used for disease diagnosis and treatment as well as in monitoring other biological processes. Metal/metal oxide based pH sensors have several advantages regarding their reliability, miniaturization, and cost-effectiveness, which are critical characteristics for in vivo applications. In this work, WO3 nanoparticles were electrodeposited on flexible substrates over metal electrodes with a sensing area of 1 mm(2). These sensors show a sensitivity of -56.7 ± 1.3 mV/pH, in a wide pH range of 9 to 5. A proof of concept is also demonstrated using a flexible reference electrode in solid electrolyte with a curved surface. A good balance between the performance parameters (sensitivity), the production costs, and simplicity of the sensors was accomplished, as required for wearable biomedical devices.
authors.affiliation: Departamento de Ciência dos Materiais, CENIMAT/I3N and CEMOP/Uninova, †REQUIMTE, and ‡Departamento de Física, CEFITEC, Faculdade de Ciências e Tecnologia-Universidade Nova de Lisboa , 2829-516 Caparica, Portugal.
authors.forename: Lídia
authors.initials: L
authors.lastname: Santos
authors.forename: Joana P
authors.initials: JP
authors.lastname: Neto
authors.forename: Ana
authors.initials: A
authors.lastname: Crespo
authors.forename: Daniela
authors.initials: D
authors.lastname: Nunes
authors.forename: Nuno
authors.initials: N
authors.lastname: Costa
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Fonseca
authors.forename: Pedro
authors.initials: P
authors.lastname: Barquinha
authors.forename: Luís
authors.initials: L
authors.lastname: Pereira
authors.forename: Jorge
authors.initials: J
authors.lastname: Silva
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Martins
authors.forename: Elvira
authors.initials: E
authors.lastname: Fortunato
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002021:Buffers; D002470:Cell Survival; D002522:Chlorocebus aethiops; D004396:Coloring Agents / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D004595:Electroplating; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D014414:Tungsten / Q000737:chemistry*; D014709:Vero Cells
chemical_list: D002021:Buffers; D004396:Coloring Agents; D004573:Electrolytes; D010087:Oxides; C511604:tungsten oxide; D014414:Tungsten