Visible-Light-Assisted Gasochromic Sensing of Nicotine from Cigarette Smoke by Metal-Organic Nanotube

Nicotine, being a major constituent of secondhand smoke (SHS) or cigarette smoke, is quite harmful for human health, because of its carcinogenic potential. Hence, its detection in air has become very significant. Herein, for the first time, a metal organic nanotube (MONT) is being used for the detection of nicotine from cigarette smoke at room temperature. MONT is a unique class of metal-organic framework (MOF) where independent one-dimensional tubular structures are formed. MONT, [Zn3(btc)2(μ3-OH)(DMF)]·H2O (1), reported here, possesses distinctive structural features, i.e., three differently shaped porous channels (circular, star, and oval), formed by periodic linkage of btc with Zn, giving rise to the formation of a highly porous framework structure. When exposed to cigarette smoke in the presence of sunlight, this MONT display a gasochromic effect, i.e., a significant color change from light yellow to dark pink within just 20 s. A high sensitivity with low detection limit of ∼ 23.3 μM was witnessed. The significance of this work lies in the visible-light-assisted, fast, easy, naked-eye, specific sensing of nicotine from cigarette smoke, which is the first of its kind.