A capillary electrophoretic method for separation and characterization of carbon dots and carbon dot-antibody bioconjugates

Capillary electrophoresis (CE) coupled with UV absorbance detection has been applied as an analysis tool for carbon dots (C-dots), which were hydrothermally synthesized from precursors citric acid (CA) and ethylene diamine (EDA). An alkaline working buffer (100 mM tris acetate, pH 8.4) was found to be optimal for rapid and reliable analysis of C-dots. A calibration curve was established over a broad concentration range (0.5-10 mg/mL) with excellent linearity (R-2=0.9989). The CE method was also applied to enhance understanding of and facilitate optimization of ensuing C-dot biolabeling reactions. The novel CE method was used to confirm and quantify production of C-dot labeled antibodies. The optimum concentration of antibody for use in the labeling reaction was determined.