Nanomaterials that can perform cascading functions in the domain of rapidity and strength of self-assembly, able to immobilize a large mass with minimum energy, and generate optical signal hold potential to contain recurring oil-spills and remediation of land or water bodies. Herein, we report the stimuli-free, phase-selective immobilization of naturally occurring heavy crude oil. Molecule(s) described herein are capable of forming nanofibers with large-area junction zones and instantaneously immobilize petroleum products (PPs), and also report the event with a turn-on emission. The extraordinary efficiency of 0.4 kg immobilizer per ton of petrol and wide operational temperature range (up to 330–360 K) stems from the rapid creation of advanced assemblies having strength (>10⁵ Pa) akin to the robust polymeric fibers. Thus, this new generation of intelligent nanomaterials with ingrained information to carry out multiple and complex function in tandem offers bright prospects to control and effectively detect the oil spill menace in a proficient manner.