Propofol-induced in-situ formation of silver nanoparticles: A sensing colorimetric method.

A simple and eco-friendly colorimetric sensing method has been developed for the extremely effective detection of propofol in exhaled breath condensate (EBC). In this study, we put forward a Tollens' procedure, in which silver nanoparticles (AgNPs) were produced using propofol as a reducing agent. To verify the in-situ synthesis of AgNPs, the TEM images, and UV-Vis absorbance were recorded in the absence and presence of propofol. The solution turned from a colorless to yellow and deep yellow color due to the surface plasmon resonance absorption band of formed AgNPs. The intensity of nanoparticle absorbance was quantitatively correlated with the propofol concentration. The proposed sensor revealed good linearity over the range of 0.01-0.8 µg mL-1 at 422 nm with the detection limit of 8.8 ng mL-1 under optimum conditions. Finally, the proposed colorimetric sensor was successfully used for the determination of propofol in the EBC sample of patients receiving propofol.