Highly modular conductive threads for multiplexed detection of hazardous gases

Wearable electronics have progressed from rigid circuit boards to fibertronics, where electronic functionality is integrated directly onto textile threads, advancing their utility. However, on-body chemical hazard monitoring remains limited by the poor sensitivity, selectivity, and durability of existing fiber-based sensors. Here, we report a modular, layer-by-layer strategy to fabricate robust, crystalline, conformal, and conductive coatings of stimuli-responsive Ni-, Cu-, and Zn-coordinated hexahydroxy- or hexaimino-triphenylene metal-organic frameworks (MOFs) on cotton threads. A four-component chemiresistive array of the threads detects and differentiates five toxic gases-H₂S, SO₂, NO, NH₃, and CO-with theoretical detection limits of 43, 60, 6, 65, and 417 ppb, respectively, all below Occupational Safety and Health Administration permissible exposure limits. When embedded into personal protective equipment, the sensor patch retains functionality even under elevated humidity and after repeated washing. This modular platform technology advances the development of chemically-responsive smart garments towards multiplexed environmental monitoring of toxic chemicals.