Measuring Nicotine in Water Contaminated by Cigarette Butts: Evaluation of a Luminescent Organometallic Network

Cigarette butts are the world's leading source of litter, disrupting water quality and the normal development of ecosystems. Tobacco use in its various forms is the leading preventable cause of death, illness, and disability worldwide. Nicotine (NCT), a natural alkaloid found in tobacco plants, is a psychoactive substance and the primary component responsible for the addictive properties of such products. Since NCT is an analyte with low native fluorescence, the use of a fluorophore that interacts with it is necessary for its quantification by molecular fluorescence. This work describes, for the first time, a method to determine NCT based on the enhancement of fluorescence of the metal-organic framework (MOF) europium terbium 2-phenylsuccinate (Eu-Tb-PSA), at λ_em = 611 nm (λ_exc = 280 nm). The experimental variables that influence the quantification of NCT were studied and optimized. Under optimal working conditions, a LOD of 12.7 ng L^-1 and a LOQ of 38.5 ng L^-1 were obtained. The calibration shows a linear behavior of three orders of magnitude for NCT concentration from 38.5 to 8.95 × 103 ng L^-1. The methodology was applied to determine trace amounts of NCT (ppb) in natural water samples.