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CN-121994894-A - Suspended graphene field effect transistor, preparation method thereof and application thereof in biosensor

CN121994894ACN 121994894 ACN121994894 ACN 121994894ACN-121994894-A

Abstract

The invention belongs to the technical field of biomarker detection, and particularly relates to a suspended graphene field effect transistor, a preparation method thereof and application thereof in a biosensor. The suspended graphene field effect transistor comprises a substrate, an insulating layer, an electrode layer, a source electrode and a drain electrode, wherein the insulating layer is arranged on the upper surface of the substrate except the groove, the side wall of the groove and the bottom surface of the groove, the electrode layer is arranged on the upper surface of the insulating layer, the source electrode and the drain electrode are respectively arranged on the upper surfaces of the insulating layers on two sides of the groove, the single-layer graphene film is arranged on the upper surface of the electrode layer, and the single-layer graphene film covers the groove and is communicated with the source electrode and the drain electrode. The suspended graphene field effect transistor provided by the invention can realize miR-21 detection without a marker, has high detection sensitivity and low detection limit, can realize miR-21 detection with femtomolar magnitude, and provides a technical approach for promoting early cancer diagnosis.

Inventors

  • ZHUANG PINGPING
  • DENG ZHIMING

Assignees

  • 集美大学

Dates

Publication Date
20260508
Application Date
20260211

Claims (10)

  1. 1. The suspended graphene field effect transistor is characterized by comprising a substrate, an insulating layer, an electrode layer and a single-layer graphene film, wherein the upper surface of the substrate is provided with a groove, the insulating layer is arranged on the upper surface of the substrate except the groove, the side wall of the groove and the bottom surface of the groove, the electrode layer is arranged on the upper surface of the insulating layer and comprises a source electrode and a drain electrode, the source electrode and the drain electrode are respectively arranged on the upper surfaces of the insulating layers on two sides of the groove, and the single-layer graphene film is arranged on the upper surface of the electrode layer, covers the groove and is communicated with the source electrode and the drain electrode.
  2. 2. The suspended graphene field effect transistor according to claim 1, wherein the electrode layer is made of gold simple substance, and the thickness of the electrode layer is 40-60 nm.
  3. 3. The suspended graphene field effect transistor according to claim 1 or 2, wherein the substrate is a Si substrate and the insulating layer is a SiO 2 layer.
  4. 4. The method for manufacturing the suspended graphene field effect transistor according to any one of claims 1-3, which is characterized by comprising the following steps: Etching a groove on the upper surface of a substrate, preparing an insulating layer, depositing an electrode material film, patterning the electrode material film to obtain a source electrode and a drain electrode, and obtaining an electrode layer on the upper surface of the insulating layer; transferring the single-layer graphene film to the upper surface of the electrode layer, covering the groove, and simultaneously communicating the source electrode and the drain electrode to obtain a semi-finished device; and carrying out annealing treatment on the semi-finished product device to obtain the suspended graphene field effect transistor.
  5. 5. The method according to claim 4, wherein the annealing treatment is performed in a reducing atmosphere comprising hydrogen and an inert gas, and the annealing treatment is performed at a temperature of 150 to 180 ℃.
  6. 6. The preparation method of the electrode material film is characterized in that the single-layer graphene film is prepared by adopting a chemical vapor deposition method, the etching method of the groove is combined with photoetching and inductively coupled plasma etching, and the deposition method of the electrode material film comprises electron beam evaporation or magnetron sputtering.
  7. 7. Use of the suspended graphene field effect transistor according to any one of claims 1 to 3 or the suspended graphene field effect transistor prepared by the preparation method according to any one of claims 4 to 7 in the preparation of a biosensor for detecting a biomarker.
  8. 8. A biological detection kit, which is characterized by comprising the suspended graphene field effect transistor according to any one of claims 1-3 or the suspended graphene field effect transistor prepared by the preparation method according to any one of claims 4-6, a surface functionalization reagent and a detection probe.
  9. 9. The biological detection kit according to claim 8, wherein the surface functionalization reagent is a solution of N-hydroxysuccinimide ester of 1-pyrenebutyric acid, the detection probe is an amino modified DNA probe, and the nucleotide sequence of the amino modified DNA probe is shown as SEQ ID NO. 2.
  10. 10. The biosensor is characterized by comprising the suspended graphene field effect transistor according to any one of claims 1-3 or the suspended graphene field effect transistor prepared by the preparation method according to any one of claims 4-7, and a detection probe modified on the surface of the single-layer graphene film.

Description

Suspended graphene field effect transistor, preparation method thereof and application thereof in biosensor Technical Field The invention belongs to the technical field of biomarker detection, and particularly relates to a suspended graphene field effect transistor, a preparation method thereof and application thereof in a biosensor. Background Early detection of cancer depends to a large extent on molecular markers that identify the onset of malignant transformation in response. Among these biomolecules, microribonucleic acid (miRNA) has become an important regulator of gene expression and is involved in tumor development, progression and metastasis. microRNA-21 (miR-21) is one of the most commonly upregulated oncogenic miRNAs, and is closely related to the development of breast cancer, liver cancer and several other solid tumors. Because of their close correlation between disease stage and clinical prognosis, miR-21 is widely recognized as a very valuable biomarker for early diagnosis and therapy monitoring. Therefore, the ability to detect miR-21 quickly, sensitively and without additional molecular markers is of great significance for improving clinical outcome. However, current detection standards, such as quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA), rely on multi-step sample preparation and enzyme amplification, often face limitations in sensitivity and complexity of the procedure. Disclosure of Invention The invention aims to provide a suspended graphene field effect transistor, a preparation method thereof and application thereof in a biosensor, and the suspended graphene field effect transistor provided by the invention can realize miR-21 detection without marking, has high detection sensitivity and low detection limit, can realize miR-21 detection in femtomolar magnitude, and provides a technical approach for promoting early cancer diagnosis. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a suspended graphene field effect transistor which comprises a substrate, an insulating layer, an electrode layer and a single-layer graphene film, wherein the upper surface of the substrate is provided with a groove, the insulating layer is arranged on the upper surface of the substrate except the groove, the side wall of the groove and the bottom surface of the groove, the electrode layer is arranged on the upper surface of the insulating layer and comprises a source electrode and a drain electrode, the source electrode and the drain electrode are respectively arranged on the upper surface of the insulating layer on two sides of the groove, and the single-layer graphene film is arranged on the upper surface of the electrode layer, covers the groove and is communicated with the source electrode and the drain electrode. Preferably, the electrode layer is made of gold simple substance, and the thickness of the electrode layer is 40-60 nm. Preferably, the substrate is a Si substrate, and the insulating layer is a SiO 2 layer. The invention provides a preparation method of the suspended graphene field effect transistor, which comprises the following steps: Etching a groove on the upper surface of a substrate, preparing an insulating layer, depositing an electrode material film, patterning the electrode material film to obtain a source electrode and a drain electrode, and obtaining an electrode layer on the upper surface of the insulating layer; transferring the single-layer graphene film to the upper surface of the electrode layer, covering the groove, and simultaneously communicating the source electrode and the drain electrode to obtain a semi-finished device; and carrying out annealing treatment on the semi-finished product device to obtain the suspended graphene field effect transistor. Preferably, the annealing treatment is performed in a reducing atmosphere, the reducing atmosphere comprises hydrogen and inert gas, and the temperature of the annealing treatment is 150-180 ℃. Preferably, the single-layer graphene film is prepared by adopting a chemical vapor deposition method, the etching method of the groove is combined with photoetching and inductively coupled plasma etching, and the deposition method of the electrode material film comprises electron beam evaporation or magnetron sputtering. The invention provides the application of the suspended graphene field effect transistor or the suspended graphene field effect transistor prepared by the preparation method in the technical scheme in the preparation of the biosensor for detecting the biomarker. The invention provides a biological detection kit, which comprises the suspended graphene field effect transistor prepared by the technical scheme or the preparation method of the technical scheme, a surface functionalization reagent and a detection probe. Preferably, the surface functionalization reagent is 1-pyrenebutyric acid N-hydroxy