Preparation and characterization of 5,10,15,20‐tetraphenylporphyrin Langmuir films for gas chemsensor applications

Abstract

In this work is reported the preparation and characterization of 5,10,15,20-tetraphenylporphyrin (H 2 TPP) films at the water-air interfaces. The surface pressure-area isotherms (π -A) and UV-Vis spectroscopy were used to investigate the effect of the spreading methods and parameters on the porphyrin monolayer formation. Also, Langmuir-Blodgett (LB) and LangmuirSchaefer (LS) films were deposited onto glass substrates in order to study the conformation changes in porphyrin molecular packing. Quartz crystal microbalance (QCM) was utilized as the active solid substrate for the development of the NO 2 gas sensor based on the H 2 TPP molecular films. The results of π -A curves have clearly shown the significant contribution of the preparation methods and processing parameters on the conformation of porphyrin molecular films. The UV-Vis spectroscopy results using polarized absorption dichroism have indicated different molecular packing for porphyrin films deposited by LB and LS methods, with relative tilted angles of 50• ± 5• and 35• ± 5 • , respectively. Moreover, the QCM response has given strong evidence that H 2 TPP porphyrin molecular films have performed as NO 2 chemsensor.

Porphyrin-based sensor nanoarchitectonics in diverse physical detection modes

“…Mansur et al prepared a Langmuir film of 5,10,15,20tetraphenylporphyrin and transferred it to a QCM sensor for detection of NO 2 gas. 156 Capan et al reported gas sensing properties of LB films of metal free 2,3,7,8,12,13,17,18octaethyl-21H,23H-porphine and its derivatives containing iron chloride, cobalt and magnesium. 157 Sensing capabilities of these thin films for volatile organic compounds such as chloroform, benzene, toluene and ethyl alcohol were investigated using the QCM technique.…”

Metalloporphyrin-Based Metal–Organic Frameworks for the Ultrasensitive Chemiresistive Detection of NO2: Effect of the Central Metal on Tuning the Sensing Performance

“…It is worth noting that, in any case, MPor, as a typical organic semiconductor, is more sensitive to NO 2 than the Zr 6 cluster. As a matter of fact, the sensing performance of PCN-222-Cu is significantly improved compared to those of metalloporphyrin-based molecular semiconductors. − This is not only attributed to the unique one-dimensional mass transfer channel offered by PCN-222-M that can promote continuity of the conductive pathway of the sensing system, but more importantly the formation of MPor/Zr 6 cluster hybrid materials that provide a free hole reservoir (buffer effect) at the MPor/Zr 6 interface to boost the sensing performance …”

Phthalocyanine and Porphyrin Derivatives and Their Hybrid Materials in Optical Sensors Based on the Phenomenon of Surface Plasmon Resonance

“…The method of film deposition is chosen depending on the properties of the compounds. Films of porphyrins and phthalocyanines soluble in organic solvents are deposited by spin coating [1], Langmuir-Blodgett (LB), and Langmuir-Schaefer (LS) [32][33][34] methods, while compounds that are volatile in a vacuum are deposited by vacuum deposition methods, namely physical vapor deposition (PVD) or organic molecular beam deposition (OMBD) [35,36]. To prepare active layers for SPR sensors, thin films of porphyrins and phthalocyanines of various metals are deposited on a substrate covered with gold or silver.…”