Design and characterization of high performance fluorescent probe for neutral red based on fluorescein monoaldol-3-acetyl coumarin

•Fluorescent organic small molecule probes for the detection of neutral red substances were developed for the first time.•The probe is bound to the neutral red by ionic bonding while FRET occurs, resulting in quenching of the fluorescence.•It has good water solubility and has been successfully applied to the detection of neutral red content in real water samples.