A novel, sensitive, rapid, and simple fluorescent probe has been developed based on green-synthesized carbon dots (CDs). In this work, CDs have been synthesized from valerian root by hydrothermal method. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) results confirm the formation of CDs with sizes of less than 10 nm. Fluorescence quenching of CDs was due to the aggregation of the negative charges of CDs with the positive charge of imipramine (IMI) and was then used as the signal for determination of IMI. In addition, the cytotoxicity of CDs was determined using the MTT assay. The probe responses under optimum conditions were linear in the range of 1.0–200.0 ng mL⁻¹ with a limit of detection of 0.6 ng mL⁻¹. Afterwards, mesoporous boehmite (MB) was modified with synthesized CDs (CDs/MB). TEM images confirmed MB modification with CDs. In this case, the …