Radiation-Tolerant Thin-Film Electrodes for pH Monitoring in Sterile Media.
Anal Chem
; 94(45): 15535-15540, 2022 11 15.
Article
em En
| MEDLINE
| ID: mdl-36332202
ABSTRACT
Thin-film pH electrodes on thermoplastic substrates can be subjected to γ-radiation (up to 45 kGy) without loss of stability or sensing performance, with important ramifications for monitoring analytes in sterile environments. pH-sensing membranes composed of polyvinyl chloride (PVC), trioctyl trimellitate (TOTM), and a standard hydrogen ionophore were cast onto screen-printed carbon electrodes with exfoliated graphene as a solid contact. Irradiated thin-film electrodes were conditioned in phosphate buffers and monitored for up to 3 months for changes in voltage readout and pH sensitivity, relative to untreated controls. The sensitivities of both irradiated and control electrodes were consistently Nernstian over a 100 day window, with both types exhibiting logarithmic voltage decays but in opposite directions. The γ-irradiated electrodes had excellent long-term stability with quasi-linear voltage drifts of +0.28 mV (â¼0.005 pH) per day. Voltage readouts from sterilized thin-film electrodes in cell culture media could be converted by single-point calibration into pH values that fell within 0.07 units relative to a commercial pH meter (calibrated daily).
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Base de dados:
MEDLINE
Assunto principal:
Cloreto de Polivinila
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Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article