摘要： Herein, we report on the ultra-high sensitive and selective detection of dopamine (DA) at pico-molar level by a low cost sensing platform based on graphene oxide (GO) sheets anchored with tungsten disulfide quantum dots (WS2 QDs). The liquid phase exfoliated WS2 QDs are mostly bilayer type with an average particle size ~2.0 ± 0.3 nm, while the GO sheets are of few-layer thickness. The WS2 QDs are highly luminescent with photoluminescence (PL) quantum yield of ~15% and they exhibit excitation wavelength dependent spectral shift in PL due to the high degree of edge/defect states. In presence of GO, the PL intensity of WS2 QDs partially quenches due to van der Waals interaction and excited-state charge transfer from WS2 to GO. However, in the presence of DA, drastic quenching of PL occurs for WS2/GO hybrid and this enables selective detection of DA as low as 10 pM, which is the lowest among the reported values. We present a new model to quantitatively explain the GO mediated efficient charge transfer and unusual quenching of PL as a function of the DA concentration. Finally, the WS2/GO based sensor is utilized for the detection of DA in the river water and blood serum with a satisfactory recovery, which establishes its practical utility as an efficient environmental/biochemical sensor.