Extensive use of pesticides in agriculture can lead to environmental pollution and potentially adverse health effects. A fluorescence Turn‐On molecular switch, derived from naturally occurring α‐mangostin (MN), isolated from the pericarp of mangosteen fruit and Graphene Quantum Dots (GQDs) synthesized from honey, was developed for the detection of carbofuran‐an organic toxic carbamate pesticide. GQDs derived from honey shows a strong fluorescence emission centered at 430 nm, which was efficiently quenched by the addition of MN. The quenching of fluorescence of GQDs by the addition of MN (OFF state) and the regaining of quenched fluorescence of GQDs‐MN system (ON state) upon the addition of the pesticide carbofuran was utilized as a detection strategy for the toxic pesticide carbofuran.