A new approach to fluorescence "turn-on" sensing of alpha-amino acids

For the first time, a conjugated fluorescent polymer was utilized to probe alpha-amino acids, sensitively and selectively, through a new approach. First the strong fluorescence of the prepared polyfluorene (P1) was quenched by trace copper ions, and then the quenched fluorescence was recovered upon the addition of alpha-amino acids, making P1 a new and sensitive biosensor toward alpha-amino acids. The experimental results demonstrated that the alpha-amino acid selective nature of P1 over other analytes was relatively good. Thus, the work reported here might open up a new avenue for developing new biosensors.