Picomolar detection with optofluidic spectroscopy on-chip

An on-chip optofluidic sensor based on liquid jet waveguide has been developed. Laser induced fluorescence takes advantage of the waveguiding nature of a jet stream to detect, at very low detection limits, common fluorophore. Tests performed on eosin Y in water demonstrated detection at 38 pM level. The proposed approach provides high excitation and collection efficiency of the sample under analysis, avoiding, at the same time, background noise that commonly affects fluorescence spectroscopy of liquids.