Nanocomposite-Structured Sensing Interfaces on Fibrous Substrates for Chemiresistive Detection of VOCs

Abstract

Highlights What are the main findings? Developed composition-programmable binary and ternary nanocomposite sensing interfaces on fibrous substrates that achieve high sensitivity and sub-ppm detection of volatile organic compounds (VOCs). Established interfacial polarity design rules where hydrophilic GE/CMC and amphiphilic GE/HEC interfaces enhance polar VOC responses, whereas hydrophobic gold thiolate assemblies target nonpolar analytes. What are the implications of the main findings? Demonstrates a versatile strategy to modulate VOC affinity and sensor stability through physical integration, preserving cellulose matrix integrity while governing charge-transport pathways. Provides actionable guidelines for creating low-cost, scalable, and reduced-complexity paper-based chemiresistive sensor arrays ideal for portable environmental and occupational monitoring. Abstract Nanocomposite-structured sensing interfaces were developed on fibrous substrates for chemiresistive detection of volatile organic compounds (VOCs) by integrating graphene (GE), cellulose derivatives hydroxyethylcellulose (HEC) and carboxymethylcellulose (CMC) and molecularly linked gold nanoparticles into composition-programmable thin films. Raman and infrared spectroscopy confirm that graphene incorporation occurs through physical integration without chemical modification of the polymer matrix, preserving cellulose integrity while enabling graphene loading to govern electrical percolation and charge-transport pathways. Systematic variation in nanocomposite composition reveals clear design rules linking interfacial polarity to VOC class sensitivity: hydrophilic GE/CMC and amphiphilic GE/HEC interfaces exhibit enhanced responses to polar and hydrogen-bonding VOCs, whereas hydrophobic gold thiolate assemblies preferentially respond to nonpolar aromatic and aliphatic VOCs. Incorporation of ligand-functionalized gold nanoparticles introduces an additional tunability dimension, modulating both VOC affinity and sensor stability through combined electronic and surface-chemical effects. Sensor arrays constructed from complementary nanocomposite interfaces achieve reliable VOC discrimination, as demonstrated by sensitivity patterns, spider-chart analysis, and principal component analysis, with effective separations retained even in reduced-sensor configurations. Across multiple nanocomposite architectures, enhanced response sensitivity is observed at low VOC concentrations, highlighting the role of interfacial adsorption dynamics and underscoring the potential of paper-based nanocomposite chemiresistive platforms for sub-ppm VOC detection.