No-interfered and visual evaluation of global warming impacts on phytoplankton-based copper bioavailability and then carbon sequestration.

ABSTRACT

Global warming has an increasingly serious impact on the ecological environment. Copper bioavailability plays an important physiological role in revealing the mechanism of carbon cycle, photosynthesis, and respiration. Here we reported a multifunctional carbon quantum dots fluorescence probe for no-interfered and visual determination of phytoplankton-based intracellular Cu(II), glucose, and reactive oxygen species (ROS). Glucose and ROS were explored to reflect the change in primary biomass and carbon sequestration. H2O2 is acted as the standard material of ROS, and the fitting parameter for glucose and H2O2 concentrations was 0.42(r = 0.9972). Both glucose, ROS, and Cu2+ detection have advantages of wide linear range (24.8-3.96 × 105 µg/L, 6-9.6 × 105 ng/L and 5-15 × 103 nmol/L, respectively), high precision (1.22 %, 6.38 %, and 7.37 %, respectively), and low detection limit (86.7 ng/L, 5.32 ng/L, and 0.367 nmol/L, respectively). Cu2+ uptake was increased with the increasing of temperature, and the copper bioavailability in increasing order was Cu-PorPhyr > Cu-phthalate > Cu-EDTA. There were significant positive correlation between glucose and Cu2+(r = 0.9943). Copper bioavailability would directly affect the carbon sequestration, i.e., when the concentration of intracellular copper increases by 1 mg/L, the content of intracellular glucose increases by 412 mg/L approximately, equally to 2.47 g/L of carbon dioxide was fixed.