Digital microfluidic bio-detection device based on a gan hemt sensor

Abstract

The application discloses a digital microfluidic biological detection device based on a GaN HEMT sensor, which comprises a GaN HEMT sensor, and a reagent droplet detection area is arranged at the lower part of the GaN HEMT sensor; when a droplet carrying an antigen is put into the device, the droplet is driven by applying a voltage on the electrode to change the contact angle of the droplet; when the droplet carrying the antigen to be detected passes through the detection area, the antigen in the droplet is combined with the antibody in the detection area, and the combination causes the change of the two-dimensional electron gas concentration in the potential well; the change of the two-dimensional electron gas concentration causes the change of the current between the source and the drain of the transistor; therefore, the change of the concentration of the introduced antigen to be detected can be detected through the change of the current; compared with the prior art, the application has the advantages that the reagent amount can be accurately controlled, the consumption of the reagent is reduced, and several droplets can be individually or simultaneously controlled to complete the detection according to the specified path, and the application has great flexibility.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microelectronics, and particularly relates to a digital microfluidic biological detection device based on a GaN HEMT sensor. BACKGROUND

[0002] GaN-based biosensors are widely studied due to their non-toxicity, good thermal and chemical stability, etc. At present, there are few biological detection devices using GaN HEMT sensors, and the actual use is not widespread. Generally, when using the sensor for biological detection in the experimental research stage, a certain amount of to-be-detected solution can be taken by a dropper and added to the gate detection area, and the concentration change of the to-be-detected substance can be detected through the current change between the source and the drain. A practical direction of the sensor is to package it into a detection device such as a blood glucose meter, which can directly obtain the result by adding the to-be-detected biological reagent to the detection port during use. Such a device is simple to operate and has high practicability.

[0003] Defects in the prior art:

[0004] 1. The direct sampling method cannot accurately control the amount of reagent, and the consumption of reagent is large.

[0005] 2. The centralized detection method cannot operate the droplets individually, and the function is single and the flexibility is low. SUMMARY

[0006] The technical problem to be solved by the present application is to overcome the above technical defects, and to provide a digital microfluidic biological detection device based on a GaN HEMT sensor, which has small reagent consumption and high flexibility.

[0007] In order to solve the above problems, the technical scheme of the present application is as follows: a digital microfluidic biological detection device based on a GaN HEMT sensor, comprising a substrate one, and a substrate two arranged at the lower part of the substrate one;

[0008] The substrate one comprises a GaN HEMT sensor device and an EWOD chip assembly;

[0009] The GaN HEMT sensor device is sequentially provided with a substrate one, a GaN layer and an AlGaN layer from top to bottom, a two-dimensional electron gas is formed between the GaN layer and the AlGaN layer, and a source electrode, a drain electrode and a gate electrode are arranged at the lower part of the AlGaN layer;

[0010] A passivation layer is arranged at the lower part of the GaN HEMT sensor device except the gate electrode, and the source electrode and the drain electrode are led out by using metal on the passivation layer;

[0011] An antibody is arranged at the lower part of the gate electrode, and an insulating layer one is arranged at the lower part of the source electrode and the drain electrode.

[0012] The EWOD chip assembly comprises a driving electrode one, and the driving electrode one is located at the lower part of the passivation layer.

[0013] The lower part of the insulating layer one and the driving electrode one is provided with a hydrophobic layer one.

[0014] The substrate two comprises a base two, and the upper part of the base two is provided with a plurality of driving electrode twos, the outer part of the driving electrode twos is provided with an insulating layer two, and the upper part of the insulating layer two is provided with a hydrophobic layer two.

[0015] Further, the material of the base one is sapphire, silicon or silicon carbide.

[0016] Further, the material of the base two is transparent glass.

[0017] Further, the material of the driving electrode one and the driving electrode two is light-transmitting metal.

[0018] Further, the light-transmitting metal is ITO.

[0019] Further, the plurality of driving electrode twos are independent of each other.

[0020] Further, the ohmic contact metal is used as the source and the drain on the AlGaN layer.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1. The device uses the EWOD chip as the carrier for reagent control, when the droplet carrying the antigen is put into the device, the specified volume of the droplet can be distributed for detection through the on-off of the electrode, and the size of the electrode can be adjusted to realize the control of microliter or even nanoliter level droplet. Therefore, the device can accurately control the reagent amount and reduce the consumption of reagents.

[0023] 2. The device is based on the GaN-based biosensor, and the detection area of the reagent droplet is set, and the antibody for detecting the antigen is fixed in the detection area. When the droplet carrying the antigen is driven to the reagent droplet detection area by the EWOD chip, the antigen in the droplet will combine with the antibody on the sensor, and after combination, the detection can be carried out through the source and drain electrodes of the device. After the detection is completed, the droplet can be driven to leave the detection area to carry out the next experimental operation. The device can drive the droplet to move along the specified path, and also can separate and combine the droplet, so it has great flexibility. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present application;

[0025] Figure 2 It is a top view of the present application;

[0026] Figure 3 A schematic diagram for driving droplets of the EWOD chip of the application;

[0027] In the figure: 1, substrate one; 2, GaN layer; 3, AlGaN layer; 4, two-dimensional electron gas (2DEG) 5, source; 6, drain; 7, gate; 8, antibody; 9, passivation layer; 10, insulating layer one; 11, driving electrode one; 12, hydrophobic layer one; 13, substrate two; 14, driving electrode two; 15, insulating layer two; 16, hydrophobic layer two. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the application. EMBODIMENT

[0029] Please refer to Figures 1-3 The application provides a technical solution: a digital microfluidic biological detection device based on a GaN HEMT sensor, comprising a substrate one, wherein the lower part of the substrate one is provided with a substrate two;

[0030] The substrate one comprises a GaN HEMT sensor device and an EWOD chip assembly, the material of GaN has no toxicity, higher chemical and thermal stability, and higher sensitivity, and the EWOD chip serves as a carrier for reagent control;

[0031] The GaN HEMT sensor device is sequentially provided with a substrate one 1, a GaN layer 2, and an AlGaN layer 3 from top to bottom, a two-dimensional electron gas 4 is formed between the GaN layer 2 and the AlGaN layer 3, and the lower part of the AlGaN layer 3 is provided with a source 5, a drain 6, and a gate 7;

[0032] The lower part of the GaN HEMT sensor device is provided with a passivation layer 9 except for the gate 7, the source 5 and the drain 6 are led out by using metal on the passivation layer 9, the source 5 and the drain 6 are used for detecting current, and the passivation layer can improve the performance of the HEMT device and protect the device;

[0033] The lower part of the gate 7 is provided with an antibody 8, the lower part of the source 5 and the drain 6 is provided with an insulating layer one 10, the gate 7 and the antibody 8 are combined as a detection area, and reagent droplets are detected in this area;

[0034] The EWOD chip assembly comprises a driving electrode one 11, the driving electrode one 11 is located in the lower part of the passivation layer 9, and the driving electrode one 11 is used for driving reagent droplets;

[0035] The lower part of the insulating layer one 10 and the driving electrode one 11 is provided with a hydrophobic layer one 12, the hydrophobic layer one 12 can make the droplets have a larger contact angle, which is conducive to the driving of the reagent droplets;

[0036] The second substrate 13 is provided with a plurality of driving electrodes 14 on the upper portion of the second substrate 13, and the driving electrodes 14 are externally provided with an insulating layer 15, and the upper portion of the insulating layer 15 is provided with a hydrophobic layer 16, the insulating layer 15 is used to accumulate electric charges, and the contact angle of the liquid drops is changed, and the hydrophobic layer 16 can make the liquid drops have a larger contact angle, which is beneficial to the driving of the liquid drops.

[0037] As shown in Figure 1 The material of the first substrate 1 is sapphire or silicon carbide.

[0038] As shown in Figure 1 The material of the second substrate 13 is transparent glass, and the transparent glass substrate is used, which is convenient for observing the movement of the reagent liquid drops when the driving electrodes drive the reagent liquid drops to move.

[0039] As shown in Figure 1 The ohmic contact metal is used as the source 5 and the drain 6 on the AlGaN layer 3.

[0040] As shown in Figure 1 The material of the driving electrodes 11 and 14 is light-transmitting metal, and the transparent material is used, which is convenient for observing the movement of the reagent liquid drops.

[0041] As shown in Figure 1 The light-transmitting metal is ITO.

[0042] As shown in Figure 1 The gate 7 is made by using a special process, and the gate 7 is combined with the antibody 8, and the special process is different because the biological antibodies detected are different, and the manufacturing method is also different. This patent introduces a GaN HEMT gate manufacturing method for detecting prostate specific antigen PSA which has been reported, which anchors the antibody of PSA in the gate region by forming a carboxylic succinimidyl ester bond with the fixed mercaptoacetic acid. Experiments have proved that when the antigen is combined with the antibody on the gate, the two-dimensional electron gas (2DEG) will change.

[0043] As shown in Figure 3 The EWOD chip is used as a carrier for reagent control, and the liquid drops are driven by changing the contact angle of the liquid drops by applying voltage on the electrodes. Specifically, when voltage is applied on one side of the electrode, the contact angle of the liquid drops will change, and on the other side, the contact angle of the liquid drops will not change because there is no voltage. Because the contact angles of the liquid drops on both sides are different, a pressure difference is generated inside the liquid drops to drive the movement of the liquid drops.

[0044] In specific use:

[0045] A kind of digital microfluidic biological detection device based on GaN HEMT sensor, antibody 8 is made on GaN HEMT biosensor, the whole device includes two circuits, one end of one road is connected respectively on droplet driving electrode 14 of EWOD chip and driving electrode 11 on substrate 1 11, for droplet driving.For biological detection, the other end is connected respectively on source electrode 5 and drain electrode 6 of GaN HEMT biosensor.Using, the droplet carrying the antigen to be measured is placed in the device, and the droplet carrying the antigen to be measured is made to pass through GaN HEMT biosensor by driving droplet, the antigen in the droplet will be combined with antibody 8 on the sensor, after combination, the change of the concentration of two-dimensional electron gas 4 in potential well will be caused, and the change of the concentration of two-dimensional electron gas 4 will cause the change of the current between source electrode 5 and drain electrode 6 of transistor, so the concentration change of the introduced antigen to be measured can be detected by the change of current.

[0046] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A digital microfluidic bio-detection device based on GaN HEMT sensor, characterized in that: The substrate one is provided with a substrate two at the lower part; The substrate one comprises a GaN HEMT sensor device and an EWOD chip assembly; The GaN HEMT sensor device is provided with a substrate one (1), a GaN layer (2) and an AlGaN layer (3) from top to bottom, a two-dimensional electron gas (4) is formed between the GaN layer (2) and the AlGaN layer (3), and a source electrode (5), a drain electrode (6) and a gate electrode (7) are provided at the lower part of the AlGaN layer (3); The lower part of the GaN HEMT sensor device is provided with a passivation layer (9) except the gate electrode (7), and the source electrode (5) and the drain electrode (6) are led out by using metal on the passivation layer (9); The lower part of the gate electrode (7) is provided with an antibody (8), and the lower part of the source electrode (5) and the drain electrode (6) is provided with an insulation layer one (10); The EWOD chip assembly comprises a driving electrode one (11), and the driving electrode one (11) is located at the lower part of the passivation layer (9); The lower part of the insulation layer one (10) and the driving electrode one (11) is provided with a hydrophobic layer one (12); The substrate two comprises a substrate two (13), a plurality of driving electrode two (14) are provided at the upper part of the substrate two (13), an insulation layer two (15) is provided outside the driving electrode two (14), and a hydrophobic layer two (16) is provided at the upper part of the insulation layer two (15).

2. The digital microfluidic bio-detection device based on GaN HEMT sensor according to claim 1, wherein: The material of the substrate one (1) is sapphire, silicon or silicon carbide.

3. The digital microfluidic bio-detection device based on GaN HEMT sensor according to claim 1, wherein: The material of the substrate two (13) is transparent glass.

4. The digital microfluidic bio-detection device based on GaN HEMT sensor according to claim 1, wherein: The material of the driving electrode one (11) and the driving electrode two (14) is light-transmitting metal.

5. The digital microfluidic bio-detection device based on GaN HEMT sensor according to claim 4, characterized in that: The light-transmitting metal is ITO.

6. The digital microfluidic bio-detection device based on GaN HEMT sensor according to claim 1, wherein: The plurality of driving electrode two (14) are independent of each other.

7. The digital microfluidic bio-detection device based on GaN HEMT sensor according to claim 1, wherein: The ohmic contact metal is used as the source electrode (5) and the drain electrode (6) on the AlGaN layer (3).

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