Abstract: The development of highly sensitive and selective room-temperature ammonia sensors remains a critical challenge for environmental and biomedical applications. We report chemiresistive sensors based on hybrid materials formed by non-covalent functionalization of pristine and carboxylated single-walled carbon nanotubes (SWCNTs and SWCNT-COOH) with chlorinated zinc phthalocyanines, specifically, tetra- (ZnPcCl4) and octa-chloro (ZnPcCl8) derivatives and unsubstituted ZnPc for comparative purposes. Comprehensive characterization by FTIR, Raman spectroscopy and ICP-AES confirmed successful hybrid formation and revealed that oxidation of SWCNTs significantly enhances phthalocyanine loading via additional hydrogen-bonding interactions. All hybrid layers demonstrated reversible chemiresistive sensor response to NH3 (1–50 ppm), with the highest performance observed for the hybrids with ZnPcCl4. Notably, SWCNT-COOH/ZnPcCl4 exhibited a 2–3-fold higher sensor response and a lower limit of detection (0.3 ppm) compared to the hybrids with pristine SWCNT (0.5 ppm), attributable to greater phthalocyanine coverage. Humidity and selectivity studies have revealed the following features: while SWCNTCOOH- based hybrids exhibit excellent sensitivity under dry conditions, their performance is affected by signal bias at high relative humidity (>40%). In contrast, SWCNT/ZnPcCl4 maintains stable characteristics. These findings highlight the impact of phthalocyanine substitution and carbon nanotube type on sensor performance, providing a foundation for designing effective ammonia sensors.

Cite: Ivanova V.N. , Krasnov P.O. , Makarenko А.М. , Basova T.V. , Klyamer D.D.
Effects of Chlorine Substitution and Nanotube Oxidation on Ammonia Detection in Zinc Phthalocyanine-SWCNT Hybrid Sensors: Experimental Studies and Quantum Chemical Calculations
Макрогетероциклы / Macroheterocycles. 2026. V.19. N1. P.41-50. DOI: 10.6060/mhc256889k

Dates:

Submitted:	Nov 21, 2025
Published print:	Jan 19, 2026

Identifiers: No identifiers

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