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

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.