Electropherogram of mixture containing QD-COOH (1) and BSA-conjugated QDs (QD-BSA) (2). CE buffer electrolyte used was 50 mM borate, pH 9.2. Gravity injection performed by elevating inlet capillary 7 cm for 5 s. Applied voltage for CE separation was 20 kV. Capillary temperature maintained at 20°C. Excitation source and detection wavelength was 473 nm and 620 nm, respectively.