Ben-David, O. published the artcileSimple Absorption Optical Fiber pH Sensor Based on Doped Sol-Gel Cladding Material, Category: benzofurans, the publication is Chemistry of Materials (1997), 9(11), 2255-2257, database is CAplus.
The construction and the operation properties of an organically doped sol-gel cladded optical fiber pH sensor, is described. The SiO2-entrapped indicator in the absorption-based device was α-naphtholphthalein, pumped with a continuous wave He-Ne 633 nm laser. The transmitted signal through the sensing fiber yields a response in the range pH = 4-11, where signal level doubled itself from base to acid. The dynamic range is high with a 100% change between these pH values, allowing pH determination in ∼0.2 pH units accuracy, better than the current status of analogous fluorescent based sensors. The high dynamic range apparently cannot be fully explained by simple evanescent field considerations. The design and setup are attractive because of the simplicity and very low cost. The probe is easily prepared under regular room conditions by simple decladding of the fiber and sol-gel recoating; the optical fiber probe is easily replaceable; the optical setup is trivial and involves inexpensive common parts, in particular the light source which can be a simple red diode laser.
Chemistry of Materials published new progress about 596-01-0. 596-01-0 belongs to benzofurans, auxiliary class Benzofuran,Naphthalene,Alcohol,Ester, name is 3,3-Bis(4-hydroxynaphthalen-1-yl)isobenzofuran-1(3H)-one, and the molecular formula is C28H18O4, Category: benzofurans.
Referemce:
https://en.wikipedia.org/wiki/Benzofuran,
Benzofuran | C8H6O – PubChem