Detection of traces of polymyxin B by “turn-on” type fluorescent reporters: The influence of the relative concentration of gold nanoparticles in a complex with rhodamine B

The detection of traces of antibiotics in the environment involves expensive and time-consuming techniques. To circumvent these drawbacks, it is investigated in this work the detection of traces of polymyxin B from fluorescence resonant energy transfer systems based on pairs of rhodamine B (donor) and citrate-capped gold nanoparticles acceptors (Au NPs) applied in the detection of analytes from the desorption of rhodamine B from Au NPs under progressive incorporation of the analyte of interest (polymyxin B). Results revealed that the sensibility of these sensors is dependent on the relative concentration of gold nanoparticles in metal-dyes complexes applied in the recovery "turn-on" of fluorescence in the presence of traces of polymyxin B, with the limit-of-detection of 3.9 ppm.