Porphyrin-embedded graphene oxide coated U-bent fiber optical probe: multiple volatile organic gas sensing protocol on a single photonic platform

In this work, we present the development of a porphyrin-embedded graphene oxide-based optical fiber sensor using evanescent wave absorption (EWA) spectroscopy for the detection of multiple environmentally hazardous volatile gases. The changes in absorption spectra in the visible region were procured when exposed to the target gases, and the obtained spectroscopic signatures for various gases were examined using an unsupervised machine-learning method. The analysis provides a protocol for grouping the spectra of similarities and forming classes to identify gas molecules. The porphyrin-embedded graphene oxide-coated U-bent fiber probe showed enhanced selection capability compared to the graphene oxide-coated probe. This low-cost photonics platform has enormous potential for developing on-field gas monitoring devices.