Due to their unique perturbation-sensitive charge transport properties, composite films of cross-linked noble metal nanoparticles show immense potential for their application as resistive sensors for physical and chemical stimuli, such as strain and volatile organic compounds (VOCs). For instance, the design of precisely patterned alkanedithiol (ADT) cross-linked gold nanoparticle films, enables their use as highly sensitive multiaxial strain sensors, suitable for wearable healthcare applications such as pulse and gesture recognition.

This presentation will focus on sensor arrays based on ADT cross-linked gold nanoparticles for the detection and recognition of VOCs and binary VOC mixtures. Due to their hybrid nature, the chemical selectivity and sensitivity of these materials can be adjusted, e.g., by the choice of nanoparticles and the organic cross-linker molecules. Engineering of the interparticle geometry by variation of the molecular cross-linker length can induce pronounced retardations of the sensors’ responses, where the obtained response times strongly depend on the analyte’s molecular size. The dynamic responses can be further adjusted by variations in film thickness, particle size, or exposure to UV radiation. These methods can be utilized for the fabrication of tailored arrays of sensors with adjusted response times. In combination with the sensors’ response amplitudes, these analyte-dependent response times can be used for the discrimination between VOCs of varying concentrations, and for the recognition of VOCs in binary mixtures, aided by multivariate analysis algorithms. Thus, these sensor arrays are promising candidates to be used as advanced chemical sensors, such as in medical diagnosis via breath analysis.