Volatile Organic Compounds sensing properties of TbPc2 thin films: Towards a plasmon-enhanced opto-chemical sensor

Abstract A sublimated film of double decker terbium(III) bis(phthalocyaninato) complex (TbPc 2 ) has been tested for optical gas sensing applications. Morphological characterization of the sensing layer has been performed by atomic force microscopy. TbPc 2 has been used as an opto-chemically interacting material to detect a class of volatile organic compounds (VOCs) following in real-time the UV–vis optical absorption variation. The interaction mechanism taking place between the investigated analytes and this double-decker-based thin films has been evaluated through the Freundlich isotherm. Additionally gold nanostructured plasmonic transducers grown onto glass substrate have been used as alternative functional substrate: the excitation of surface plasmon resonances at frequencies close to those of the bis-phthalocyanine molecular resonances has been investigated as a possible factor for increasing the sensing performances towards the investigated VOCs. By monitoring the shift of the typical localized surface plasmon resonance (LSPR) peak a plasmon-enhanced functionality is added and investigated thoroughly.