Porphyrin coated fiber optic probes for acid vapor detection

In this work the deposition of a tetrakis(4-sulfonatophenyl)porphyrin (TPPS) film onto optical fiber tip is obtained via a non-conventional procedure consisting in a UV-light induced deposition. This leads to the growth of TPPS thin films right at the core region of the fiber end. The simplicity and cost effectiveness of this procedure, as well as the potential of porphyrins as functional materials, enable the design of novel active and passive in-fiber devices. Here, the presence of intense, narrow bands in the reflected spectra is successfully exploited to detect corrosive or toxic vapors, such as strong volatile acids and bases, at room temperature.