The excess accumulation of nonessential Al 3 + in the human body can cause serious health problems, thus there is significant interest in the detection of Al 3 + . A new ratio fluorescent probe (RF-probe) based on the mixing of redemitting D-penicillamine (DPA) stabilized copper nanoclusters (DPA-CuNCs) with pyridoxal 5'-phosphate (PLP) was designed for sensitive and selective determination of Al 3 + . The À CHO group of PLP is expected to form an imine linkage with the free À NH 2 group available of the DPA on the surface of DPA-CuNCs.The content of Al 3 + could be mensurated by the as-prepared RF-probe with a linear response in the range of 1.33-46.67 μmol ⋅ L À 1 , and corresponding limit of detection (LOD) was calculated to be 0.33 μmol ⋅ L À 1 . Moreover, the RF-probe was successfully extended to the assay of Al 3 + in aluminum carbonate chewing tablets, baking powder, pond water and drink water with satisfactory results compared to the standard atomic absorption spectroscopy (AAS).