The present invention relates to a class of fluorescent, organic nanofibrils, and particularly the films comprising entangled piling of these nanofibrils exhibiting effective quenching of their fluorescence upon exposure the vapor of explosives. The invention also relates to a sensor and a method for sensing the explosives vapor and other volatile organic compounds, including the explosives taggants through the modulation of the fluorescence of the nanofibril film and the electrical conductivity of the nanofibrils. The invention also relates to a development of synthetic methods, protocols and techniques that leads to production of various arylene-ethynylene macrocycle (AEM) molecules, which consist of a shape-persistent, toroidal scaffold in planar conformation, with minimal ring strain and highly tunable ring sizes (from 0.5 nm to above 10 nm). The invention also relates to an approach to optimization of the one-dimensional molecular arrangement along the long axis of the nanofibril, which provides increased exciton (excited state) migration (via cofacial intermolecular electronic coupling) and charge transport (via pi-electronic delocalization). A combination of long-range exciton migration and efficient charge transport makes the nanofibrils ideal as sensory materials for detecting explosives and other volatile organic compounds through both optical and electrical sensing mechanisms.