Abstract: Objective　To establish a method for separating serum lipoprotein and its subclass by microchip capillary electrophoresis，and investigate the significance of clinical application.  Methods　The pre-stained lipoproteins with NBD C6-ceramide were separated by Tricine buffers with gold nanoparticles as an additive in quartz chip with laser induced fluorescence detector. The impact of gold nanoparticle with different sizes and concentrations on the separation of lipoprotein was investigated. The best electrophoresis condition was obtained. The detection limit，linearity and reproducibility were investigated. Serum lipoproteins of 30 patients with coronary heart disease (CHD) and 30 healthy subjects (control group) were separated by microchip capillary electrophoresis.  Results　The 20 nmol/L 5nm gold nanoparticles were used as an additive to the buffer in order to obtain the absolute separation of lipoproteins [large and buoyant low density lipoprotein (LDL) (lLDL)，small and dense LDL (sdLDL)，very low-density lipoprotein (VLDL) and high-density lipoprotein(HDL)]. Under optimized conditions，the linear ranges of lLDL，sdLDL，VLDL and HDL were 0.01-0.8，0.04-1.0，0.04-1.0 and 0.02-0.8 mg/L，and their limits of detection were 5，5，15 and 8 μg /L，respectively [signal-to-noise ratio (S/N) ＝ 3]. Relative standard deviation (RSD) values of the peak areas of lLDL，sdLDL，VLDL and HDL were 3.5%，2.2%，4.5% and 3.9%，respectively. The levels of sdLDL and VLDL increased significantly，and HDL decreased more significantly in CHD group than in control group.  Conclusions　The results show that nanotechnology-based microchip capillary electrophoresis is applicable for the rapid and convenient detection of lipoprotein and its subclass，and it has significance for evaluating the analysis of CHD risk factors and the early detection and prevention of CHD.

Key words: Lipoprotein, Gold nanoparticle, Microchip capillary electrophoresis, Coronary heart disease