A new N-doped carbon dots (NCDs) could be prepared by using the microwave-assisted technique within 10 min without the need for any solvent or catalyst. The NCDs exhibited a highly sensitive electrochemical response toward dopamine (DA) in Phosphate Buffered Saline (PBS) (pH = 6.5). The detection limit of DA was calculated by differential pulse voltammetry (DPV) as low as 1.2 x 10(-9) mol/L with a linear dynamic range of 5.0 x 10(-8) to 8.0 x 10(-8) mol/L. These results suggested that this new NCDs could be effectively used for the direct and rapid detection of trace levels of DA in human serum and urine samples. (C) 2015 Elsevier Inc. All rights reserved.