Capillary array electrophoresis-chemiluminescence detection coupled system

Abstract

A capillary array electrophoresis (CAE)-chemiluminescence (CL) detection coupled system includes a high-voltage power supply, a capillary array, an array channel CL reaction tank, a CAE sample tank, a CAE detection tank, a chemiluminescent reagent delivery unit, a multi-channel detection unit, and a data acquisition and processing unit. An inlet end of the capillary array is connected to the CAE sample tank. An outlet end of the capillary array is connected to the array channel CL reaction tank, and is further connected to the CAE detection tank.

Claims

1. A capillary array electrophoresis (CAE)-chemiluminescence (CL) detection coupled system, comprising: a CAE sample tank; a CAE detection tank; a capillary array; a high-voltage power supply; an array channel CL reaction tank; a chemiluminescent reagent delivery unit; a multi-channel detection unit comprising an array detector; a data acquisition and processing unit; and a computer; wherein a cathode terminal of the high-voltage power supply is connected to the CAE detection tank, and an anode terminal of the high-voltage power supply is connected to the CAE sample tank; and an inlet end of the capillary array is connected to the CAE sample tank; an outlet end of the capillary array is inserted into the array channel CL reaction tank; and the array channel CL reaction tank is connected to the CAE detection tank; a photosensitive surface of the array detector is configured to face towards the outlet end of the capillary array through an imaging lens; the data acquisition and processing unit is configured to collect a signal of individual channels of the array detector, and transmit the signal to the computer; a plurality of microchannels are provided inside the array channel CL reaction tank; an outlet end of each capillary of the capillary array is arranged in a corresponding microchannel; and the chemiluminescent reagent delivery unit is configured to deliver a chemiluminescent reagent to the plurality of microchannels to form a sheath flow around each capillary, so as to allow the chemiluminescent reagent to flow out along the outlet end of each capillary.

2. The CAE-CL detection coupled system of claim 1, wherein a top of the array channel CL reaction tank is provided with a capillary array inlet to allow the capillary array to enter the array channel CL reaction tank; the plurality of microchannels are arranged at a lower portion of the array channel CL reaction tank; a cavity is provided above the plurality of microchannels; and a side wall of the cavity is provided with a chemiluminescent reagent inlet to allow the chemiluminescent reagent to enter the array channel CL reaction tank.

3. The CAE-CL detection coupled system of claim 2, wherein the chemiluminescent reagent delivery unit comprises a chemiluminescent substrate tank, an oxidant tank and a mixer; a delivery pump is arranged inside the mixer; and the delivery pump is connected to the chemiluminescent reagent inlet.

4. The CAE-CL detection coupled system of claim 3, wherein the chemiluminescent substrate tank is configured to accommodate a chemiluminescent substrate; the oxidant tank is configured to accommodate an oxidant; the chemiluminescent substrate is selected from the group consisting of luminol, luminol derivatives and peroxyoxalate ester compounds; and the oxidant is selected from the group consisting of hydrogen peroxide, sodium peroxide, potassium peroxide, permanganate, periodate, hypochlorite, dichromate, ammonium persulfate and ceric sulfate.

5. The CAE-CL detection coupled system of claim 1, wherein the CAE detection tank is connected to an electrophoresis buffer storage tank and a waste liquid outlet.

6. The CAE-CL detection coupled system of claim 1, wherein the plurality of microchannels are arranged in a plane array or a linear array.

7. The CAE-CL detection coupled system of claim 6, wherein the number of the plurality of microchannels is 2-384; and a diameter of each of the plurality of microchannels is 200-5,000 μm.

8. The CAE-CL detection coupled system of claim 6, wherein the multi-channel detection unit further comprises the imaging lens; and the array detector is a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS) or a diode array detector (DAD).

9. The CAE-CL detection coupled system of claim 8, wherein when the array detector is CCD or CMOS, a photosensitive surface of the array detector faces towards an axial direction of the outlet end of the capillary array; when the capillary array is arranged in linear array, the array detector is DAD, and a photosensitive surface of the array detector faces towards the plurality of optical detection windows near the outlet end of the capillary array; and a length of each of the plurality of optical detection windows is 1-10 mm; and a distance between the imaging lens and the outlet end of the capillary array is a focal length of the imaging lens.

10. The CAE-CL detection coupled system of claim 1, wherein the data acquisition and processing unit comprises a data acquisition card and a data processing software; the data acquisition card is connected to the array detector, and is configured to collect the signal of individual channels of the array detector in real time and record a capillary electrophoretogram of individual channels of the array detector; and the computer is configured to perform baseline noise filtering on the capillary electrophoretogram, calculate peak area, peak height and migration time of components in individual channels of the array detector, and analyze and process sample data.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically shows a structure of a CAE-CL detection coupled system according to an embodiment of the disclosure;

(2) FIG. 2 is a side view of an array channel CL reaction tank under an axial detection mode;

(3) FIG. 3 is a sectional view of a microchannel array in the array channel CL reaction tank under the axial detection mode;

(4) FIG. 4 is a side view of the array channel CL reaction tank under a lateral detection mode;

(5) FIG. 5 is a sectional view of the microchannel array in the array channel CL reaction tank under the lateral detection mode;

(6) FIG. 6 is a capillary array electrophoretogram of horseradish peroxidase (HRP) under the axial detection mode; and

(7) FIG. 7 is a capillary array electrophoretogram of HRP under the lateral detection mode.

(8) In the drawings: 1, platinum anode; 2, platinum cathode; 3, CAE sample tank; 4, capillary array; 5, high-voltage power supply; 6, array channel CL reaction tank; 7, CAE detection tank; 8, chemiluminescent substrate tank; 9, oxidant tank; 10, mixer (including a delivery pump); 11, electrophoresis buffer storage tank; 12, imaging lens; 13, plane array detector; 14, waste liquid tank; 15, data acquisition and processing unit; and 16, computer.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiment 1

(9) The CAE detection of HRP was conducted under an axial detection mode of a CAE-CL detection coupled system (shown in FIGS. 1-3) and the capillary array electrophoretogram was shown in FIG. 6, where the capillary array consisted of five capillaries is 5; and the sample was 1.0×10.sup.−8 mol/L HRP. Referring to FIG. 6, the sample peak was observed in the 2.sup.nd-the 5.sup.th capillaries. The 1.sup.st capillary without the sample was free of the sample peak, indicating that its detection was not interfered by other capillaries (such as the 4.sup.th capillary and the 5.sup.th capillary).

(10) The capillaries were made of quartz, each having an inner diameter of 50 μm and a length of 30 cm. The electrophoresis buffer was 3.7 mmol/L sodium borate solution (pH=10.2). The CL reagent was prepared by 50 mmol/L NaHCO.sub.3 (pH=9.0), 7.5×10.sup.−3 mol/L H.sub.2O.sub.2, 7.5×10.sup.−4 mol/L luminol and 1.25×10.sup.−3 mol/L ethylenediaminetetraacetic acid (EDTA). The electrophoresis was conducted at 15 kV. As shown in FIG. 1, the sample was introduced to the capillary array 4 from the platinum anode 1, and then migrated to the platinum cathode 2 under the high electric field provided by the high-voltage power supply 5. After electrophoresis time, the separated sample flowed out of the outlet end of the capillary and met with chemiluminescent reagents (fed from the chemiluminescent substrate tank 8 and the oxidant 9) in the array channel CL reaction tank 6. The generated chemiluminescent signal was captured by an imaging lens 12 and a plane array detector 13 (CCD), and was processed with data acquisition and processing unit 15. In this case, the photosensitive surface of CCD faced towards the axial direction of the outlet end of the capillary array. The capillary array electrophoretogram was shown in FIG. 6 and was output by a computer 16.

Embodiment 2

(11) The CAE detection of HRP was conducted under a lateral detection mode of a CAE-CL detection coupled system (shown in FIGS. 1 and 4-5), and the capillary array electrophoretogram was shown in FIG. 7, where the capillary array consisted of five capillaries, and the sample was 1.0×10.sup.−8 mol/L HRP. Referring to FIG. 7, the sample peak was observed in the 1.sup.st capillary and the 3.sup.rd-5.sup.th capillaries. The 2.sup.nd capillary without sample loading was free of the sample peak, indicating that other capillaries (such as the 1.sup.st capillary and the 3.sup.rd-5.sup.th capillaries) had no interference with its detection.

(12) The capillaries were made of quartz, each having an inner diameter of 50 μm and a length of 36 cm. The electrophoresis buffer was 3.7 mmol/L sodium borate solution (pH=10.2). The CL reagent was prepared by 50 mmol/L NaHCO.sub.3 (pH=9.0), 7.5×10.sup.−3 mol/L H.sub.2O.sub.2, 7.5×10.sup.−4 mol/L luminol and 1.25×10.sup.−4 mol/L EDTA. The electrophoresis was performed at 10 kV. In this case, the photosensitive surface of CCD faced towards the lateral direction of the outlet end of the capillary array.