Fluorescence chemosensing of meldonium using a cross-reactive sensor array

In this paper, we report a fluorescence sensor array approach for the urinary detection of a prohibited substance in sport, meldonium. Four chemosensors with ethidium bromide scaffold were employed in the method. The interaction between meldonium and chemosensors was investigated by different techniques, such as ultraviolet-visible absorbance and fluorescence spectroscopy, nuclear magnetic resonance, and mass spectrometry. A molecular dynamic simulation was also used to elucidate and support the interaction mechanisms between meldonium and the chemosensors. Differential responses ob-tained from the sensor array enabled the qualitative and quantitative analysis of meldonium with low error values. The method was able to detect and quantify meldonium at the nM level, which fulfills the requirements of minimum perfor-mance defined by the World Anti-Doping Agency.