Complex sentence: Two cysteines were introduced into the beta barrel structure of the GFP, the oxidation state (reduced dithiol or the oxidized disulfide) of the engineered thiols determines the fluorescence properties of the sensor.
Split into simpler sentences: Two cysteines were introduced into the beta barrel structure of the GFP. The oxidation state (reduced dithiol or the oxidized disulfide) of the engineered thiols determines the fluorescence properties of the sensor.