One-pot synthesis of poly(vinylpyrrolidone)-encapsulated color-emitting silicon quantum dots for sensitive and selective detection of 2,4,6-trinitrophenol

Abstract

Here, we illustrate an efficient, convenient, and simple method for the sensitive and selective detection of nitro explosive 2,4,6-trinitrophenol (TNP) in 100% water medium by bright cyan-blue color emitting colloidal poly(vinylpyrrolidone)-encapsulated silicon quantum dots (PVP-Si QDs) as a fluorescent probe. PVP-Si QDs have been easily fabricated with PVP as a surface stabilizer, dispersant and reducing agent and N-[3-(trimethoxysilyl) propyl]-ethylenediamine (DAMO) as the silicon source via a one-step hydrothermal method in aqueous solution. The PVP-Si QDs showed a selective fluorescence quenching toward TNP compared with other reactive, explosive molecules and ions found widely in the environment. Under the optimized conditions, the probe exhibited an excellent linear fluorescence quenching effect towards TNP ranging from 0.5 to 80 μM with a limit of detection of 0.34 μM (based on 3s/k). The sensing pathway for the high sensitivity of the PVP-Si QD assay to quantify TNP is expected to combine the inner filter effect (IFE) and static quenching effect (SQE). Furthermore, the developed fluorescence-sensing platform quantifies a trace amount of TNP in real water and fish tissue samples.