Open AccessDevelopment of durable microelectrodes for the detection of hydrogen peroxide and pH
Author(s) -
Clark Caelen M.,
Ruszala Brandon M.,
Ehrensberger Mark T.
Publication year - 2020
Publication title -
medical devices & sensors
Language(s) - English
Resource type - Journals
ISSN - 2573-802X
DOI - 10.1002/mds3.10074
Subject(s) - microelectrode , hydrogen peroxide , electrode , materials science , cathodic protection , platinum , pipette , nanotechnology , analytical chemistry (journal) , chemical engineering , chemistry , electrochemistry , chromatography , catalysis , organic chemistry , engineering
Cathodic electrical stimulation has been investigated as a way to treat implant‐associated infection of orthopaedic devices. One of the proposed mechanisms of these effects is the changes in chemical gradients adjacent to the implant generated by the cathodic reaction products. Of these reaction products, both alkaline pH and hydrogen peroxide have been implicated as antimicrobial agents. However, direct measurement of these chemical effects has yet to be fully characterized for orthopaedic biomaterials. Microelectrodes are powerful tools that can be used to measure localized chemical conditions. Most commercially available sensors are fabricated from pulled glass pipettes, which make them quite fragile. In order to more easily make measurements of the effects of electrical stimulation, more durable sensors are desired. Solid‐state electrodes were fabricated from platinum and iridium micro‐wires to make H 2 O 2 and pH‐sensitive electrodes, respectively. Additionally, a similar method was used to fabricate electrodes that were housed within a stainless steel needle, which could be used to penetrate and measure in solid samples without damaging the sensor. The H 2 O 2 microelectrode was found to have a sensitivity of 34.1 pA/µM and a R 2 value of .996. The pH microelectrode was found to have a linear calibration from 2 to 12 with a sensitivity of 76.7 mV/pH and a R 2 of .996. The needle‐based electrodes were found to be able to detect changes in both H 2 O 2 and pH when tested in an agar gel model.