Ultra-trace level electrochemical sensor for methylene blue dye based on nafion stabilized ibuprofen derived gold nanoparticles

We report the synthesis of ibuprofen coated gold nanoparticles (ibu-AuNps) via heating a solution mixture of ibuprofen, gold chloride and sodium hydroxide at 100 °C for 15 min. The ibuprofen worked as reducing as well as capping agent under the accelerating action of sodium hydroxide and heat. Characterization of as formed ibu-AuNps was carried out with the help of Ultra Violet-visible (UV-vis) spectroscopy, atomic force microscopy (AFM) and Fourier transform infra-red (FTIR) spectroscopy. These ibu-AuNps were sandwiched between glassy carbon electrode (GCE) and nafion and used as highly responsive sensor for trace level detection of methylene blue (MB) dye under optimized conditions. The sensor was capable to perform in the linear range of 0.01-1.1 μM solution of MB dye with limit of detection (LOD) of 0.0039 μM (3.9 nM) that demonstrate an exceptionally remarkable sensitivity. The as-fabricated sensor was successfully applied for estimation of exceptionally low level concentration of MB dye in various types of water samples.