Extended Data Fig. 7: Synthesis and characterization of the optical pH sensor.
From: A swallowable X-ray dosimeter for the real-time monitoring of radiotherapy
a, Schematic of the polyaniline synthesis. In a typical procedure, aniline liquid and ammonium persulfate (APS) were added to hydrochloric acid, followed by the addition of a PDMS substrate to the solution. b, Normalized transmission spectra of the pH-sensing film at various pH levels, with emission ranging from 300 nm to 800 nm. c, Changes in G/B colour ratio versus pH. d, pH response of various devices fabricated from the same batch of polyaniline films. e, G/B colour ratio of the transmitted afterglow through the polyaniline film at different pH levels. f, Dynamic characteristics of pH sensing with afterglow. g, G/B colour ratio as a function of time at pH 3.5. In e and g, error bars show the s.d. of colour ratios.
