Carbon dots from contaminated Eichhornia crassipes roots for spectrally multiplexed identification and sensing of solvents

Abstract

Water hyacinth (Eichhornia crassipes) is an invasive aquatic plant (originally from South America) that colonizes tropical and subtropical waterbodies worldwide. In this work, we present the sustainable application of carbon dots, obtained by green chemistry from E. crassipes roots, as fluorescence-based ratiometric sensors of ethanol and acetone traces in water with a limit of detection (LOD) of ∼1% v/v and ∼0.03% v/v, respectively. The proposed carbon nanoprobe acts as a spectrally multiplexed sensing platform to simultaneously monitor multiple spectral features associated with molecular interactions, allowing for the detection of methanol-spiked ethanol under laboratory conditions with a LOD of ∼1.4% v/v. The viability of the multi-responsive sensor has also been tested in methanol-adulterated commercial alcoholic beverages. The solvation effect of the proposed CDs in different surrounding systems could lead to their potential application as a straightforward, eco-friendly, and affordable alternative for the quality control of certain solvents, thereby improving accuracy, sensitivity, and selectivity compared to traditional analytical methods as well as safeguarding public health by preventing the consumption of adulterated alcoholic beverages.