Fluorescent carbon dots for probing the effect of thiram on the membrane of fungal cell and its quantitative detection in aqueous solution

It is of great significance to probe the effects of fungicides on living fungal cell using fluorescent sensors, which can provide visual evidence for their fungicidal mechanism. In this work, the effect of thiram (0.0 - 80.0 mu M) on the membrane of fungal cell was investigated by monitoring the internalizations of amine terminated carbon dots (CDs - NH2), carboxylate group coated carbon dots (CDs - COO-) and Cu2+ into cells via fluorescent imaging. Results showed that the internalizations of positively charged CDs - NH2 and Cu2+ into fungal cells were promoted by thiram at the concentration from 0.0 to 60.0 (40.0 for Cu2+) mu M, but their internalizations decreased with a further increase in thiram concentration from 60.0 (40.0 for Cu2+) to 80.0 mu M. On the other hand, the internalization of passively charged CDs - COO- was not affected by thiram. Therefore, it can be deduced that the effect of thiram on the membrane of fungal cell probed by the fluorescent carbon dots is stimulating the non-selective cation channel up to a certain point in a dose dependent manner. Additionally, an approach was built for the detection of thiram with high sensitivity and selectivity in the presence of excessive Cu2+.