Real-Time Ammonia and Humidity Monitoring with Ultra-Fast Conductometric Sensors Based on Porphyrin and Phthalocyanine Complexes
Abstract
Organic semiconductors like porphyrins and phthalocyanines are attracting a wide range of researchers due to their versatile electrical properties and sensing performances in conductometric sensors. In this study, we investigate two types of π-extended porphyrins, which share the same macrocyclic structure but differ in their central metal. These porphyrins are employed as sublayers in bilayer heterojunction devices, with the lutetium bisphthalocyanine complex, LuPc2, serving as the common top layer. Remarkably, the central metal in the porphyrin macrocycle significantly influences the solubility of the materials and, consequently, the surface topography of the resulting bilayer heterojunction devices. This structural variation translates into distinct electrical and sensing performances. The device incorporating nickel as metal centre (AM2) demonstrates superior sensitivity towards NH3, with a relative response (RR) of ca. -7% at 90 ppm, an ultra-fast response time of about 9 s, and an impressive limit of detection (LOD) of 250 ppb, whereas, the device that has zinc as metal centre in sublayer (AM3) exhibits RR value of ca. -0.9% at 90 ppm with t90 of ca. 120 s and LOD of 2 ppm. Both devices are evaluated under randomly varying NH3 concentration and RH value. The results show that the AM2-based sensor allows following NH3 in real-time, while the AM3-based sensor delivers an average concentration over time. On the other hand, the AM2-based sensor exhibits slow kinetics under RH exposure, while the AM3-based sensor precisely mirrors the pattern of random RH changes generated by the software, demonstrating its exceptional responsiveness and accuracy in tracking humidity fluctuations. These findings underscore the critical role of the metal centre in tuning the electrical and sensing properties of the heterojunction devices.
Related
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BibTeX
@article{moorthy2026realtime,
title = {{Real-Time Ammonia and Humidity Monitoring with Ultra-Fast Conductometric Sensors Based on Porphyrin and Phthalocyanine Complexes}},
author = {Sujithkumar Ganesh Moorthy and Eric Lesniewska and Hong Wang and Marcel Bouvet},
journal = {ACS Sensors},
year = {2026},
month = oct,
doi = {10.1021/acssensors.5c01698},
url = {https://hal.science/hal-05842731v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Real-Time Ammonia and Humidity Monitoring with Ultra-Fast Conductometric Sensors Based on Porphyrin and Phthalocyanine Complexes
AU - Sujithkumar Ganesh Moorthy
AU - Eric Lesniewska
AU - Hong Wang
AU - Marcel Bouvet
PY - 2026
DA - 2026/10/28
JO - ACS Sensors
DO - 10.1021/acssensors.5c01698
UR - https://hal.science/hal-05842731v1
AB - Organic semiconductors like porphyrins and phthalocyanines are attracting a wide range of researchers due to their versatile electrical properties and sensing performances in conductometric sensors. In this study, we investigate two types of π-extended porphyrins, which share the same macrocyclic structure but differ in their central metal. These porphyrins are employed as sublayers in bilayer heterojunction devices, with the lutetium bisphthalocyanine complex, LuPc2, serving as the common top layer. Remarkably, the central metal in the porphyrin macrocycle significantly influences the solubility of the materials and, consequently, the surface topography of the resulting bilayer heterojunction devices. This structural variation translates into distinct electrical and sensing performances. The device incorporating nickel as metal centre (AM2) demonstrates superior sensitivity towards NH3, with a relative response (RR) of ca. -7% at 90 ppm, an ultra-fast response time of about 9 s, and an impressive limit of detection (LOD) of 250 ppb, whereas, the device that has zinc as metal centre in sublayer (AM3) exhibits RR value of ca. -0.9% at 90 ppm with t90 of ca. 120 s and LOD of 2 ppm. Both devices are evaluated under randomly varying NH3 concentration and RH value. The results show that the AM2-based sensor allows following NH3 in real-time, while the AM3-based sensor delivers an average concentration over time. On the other hand, the AM2-based sensor exhibits slow kinetics under RH exposure, while the AM3-based sensor precisely mirrors the pattern of random RH changes generated by the software, demonstrating its exceptional responsiveness and accuracy in tracking humidity fluctuations. These findings underscore the critical role of the metal centre in tuning the electrical and sensing properties of the heterojunction devices.
SN - 2379-3694
ER -