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CN-122016979-A - Biosensor based on screen printing electrode and preparation method and application thereof

CN122016979ACN 122016979 ACN122016979 ACN 122016979ACN-122016979-A

Abstract

The invention provides a biosensor based on a screen printing electrode, and a preparation method and application thereof. The preparation method comprises the following steps of a, depositing a silicon film transition layer on the surface of a working electrode of a screen printing electrode by adopting PECVD equipment, b, spin-coating a tin dioxide solution on the surface of the silicon film transition layer to form a tin dioxide layer, c, firstly carrying out hydrogen reduction on the surface of the tin dioxide layer, then carrying out silicon nanowire growth to obtain a silicon nanowire layer, d, firstly carrying out ultraviolet ozone treatment on the silicon nanowire layer, then carrying out condensation reaction in an alcohol solution containing 3-aminopropyl triethoxysilane, carrying out heating to strengthen coupling strength after cleaning, and finally, carrying out fixation in a phosphate buffer solution containing a nucleic acid aptamer to obtain the biosensor. According to the invention, the silicon nanowires are prepared on the screen printing electrode, and then the nucleic acid aptamer is fixed, so that the electrochemical sensor for detecting the Alzheimer's disease is constructed, and the electrochemical sensor has excellent conductivity, biocompatibility and detection sensitivity.

Inventors

  • CHEN WANGHUA
  • LUO WEN

Assignees

  • 宁波大学

Dates

Publication Date
20260512
Application Date
20260416

Claims (10)

  1. 1.A preparation method of a biosensor based on a screen printing electrode is characterized by comprising the following steps: step 1, depositing a silicon film transition layer on the surface of a working electrode of a screen printing electrode by adopting PECVD equipment; step 2, spin-coating a tin dioxide solution on the surface of the silicon film transition layer to form a tin dioxide layer; Step 3, firstly carrying out hydrogen reduction on the surface of the tin dioxide layer, and then carrying out silicon nanowire growth to obtain a silicon nanowire layer; and 4, firstly carrying out ultraviolet ozone treatment on the silicon nanowire layer, then placing the silicon nanowire layer in an alcohol solution containing 3-aminopropyl triethoxysilane for condensation reaction, cleaning, then heating to enhance coupling strength, and finally placing the silicon nanowire layer in a phosphate buffer solution containing a nucleic acid aptamer for fixation to obtain the biosensor, wherein the base sequence of the nucleic acid aptamer is 5'- (CH 2 ) 4 -UAGCGUAUGCCACUCUCCUGGGACCCCCCGCCGGAUGGCCA-CAUCC-3'.
  2. 2. The method for preparing the biosensor based on the screen printing electrode according to claim 1, wherein in the step 1, the deposition condition of the silicon film transition layer is that hydrogen, silane and phosphane are introduced for coating for 2-180 min under the conditions of 25-300 ℃ of temperature, 1-50W of radio frequency power and 50-1000 Pa of pressure, wherein the flow rate of the hydrogen is 50-500 sccm, the flow rate of the silane is 0.1-50 sccm, and the flow rate of the phosphane is 0.1-10 sccm.
  3. 3. The method for preparing a biosensor based on a screen-printed electrode according to claim 1, wherein in the step 2, the concentration of the tin dioxide solution is 0.01-10%; The rotating speed of the spin coating is 100-5000 RPM, and the spin coating time is 10-120 s.
  4. 4. The method for preparing the biosensor based on the screen printing electrode according to claim 1, wherein in the step 3, the hydrogen reduction condition is that hydrogen is introduced into the biosensor for reduction for 2-30 min under the conditions that the temperature is 25-300 ℃, the radio frequency power is 10-100W, the pressure is 100-1000 Pa, and the flow rate of the hydrogen is 50-500 sccm; The growth condition of the silicon nanowire is that hydrogen, silane and phosphane are introduced into the silicon nanowire at the temperature of 232-350 ℃, the radio frequency power of 5-50W and the pressure of 150-1000 Pa, wherein the flow rate of the hydrogen is 100-500 sccm, the flow rate of the silane is 1-20 sccm, the flow rate of the phosphane is 0.1-10 sccm, and the growth time is 1-40 min.
  5. 5. The method for manufacturing a biosensor based on a screen-printed electrode according to claim 1, wherein in step 4, the volume fraction of 3-aminopropyl triethoxysilane in the alcohol solution containing 3-aminopropyl triethoxysilane is 0.5-5%; the concentration of the nucleic acid aptamer in the phosphate buffer solution containing the nucleic acid aptamer is 50-1000 nM, wherein the pH value of the phosphate buffer solution is 7.4.
  6. 6. The method for preparing the biosensor based on the screen printing electrode according to claim 1, wherein in the step 4, the time of the ultraviolet ozone treatment is 50-500 s.
  7. 7. The method for preparing the biosensor based on the screen printing electrode according to claim 1, wherein in the step 4, the temperature of the condensation reaction is room temperature, and the time is 20-60 min; The temperature of the heating and coupling strength enhancement is 100-120 ℃ and the time is 10-30 min.
  8. 8. The method for manufacturing a biosensor based on a screen-printed electrode according to claim 1, wherein in the step4, the fixed time is 1-3 hours.
  9. 9. A biosensor obtained by the method according to any one of claims 1 to 8, comprising a screen printing electrode and a biological recognition layer supported on the surface of the working electrode of the screen printing electrode, wherein the biological recognition layer comprises a silicon film transition layer and a silicon nanowire growth layer, and a nucleic acid aptamer is fixed on the surface of the silicon nanowire growth layer.
  10. 10. Use of the biosensor of claim 9 for the detection of amyloid, an biomarker for alzheimer's disease, based on an electrochemical method.

Description

Biosensor based on screen printing electrode and preparation method and application thereof Technical Field The invention relates to the technical field of biosensors, in particular to a biosensor based on a screen printing electrode, and a preparation method and application thereof. Background Alzheimer's Disease (AD) is a progressive, irreversible degenerative Disease of the central nervous system, characterized mainly by gradual loss of cognitive function, accompanied by reduced ability and behavioral impairment in daily life. AD not only severely affects the quality of life of the patient, but also creates tremendous stress on the home, society, and medical system. Typical case characteristics of AD include (1) extensive deposition of cerebral cortex and hippocampal amyloid plaques (formed by aβ peptide deposition), (2) neurofibrillary tangles (consisting mainly of hyperphosphorylated Tau protein), (3) significant reduction of neuronal numbers and synaptic loss, (4) activation of neuroinflammatory responses, (5) brain tissue atrophy, etc. Recent studies have shown that the transitional production and clearance of amyloid (aβ peptide), particularly aβ 1-42, is an early initiating factor in the initiation of changes in AD cases. Aβ 1-42 is a short peptide produced by cleavage of β -Amyloid Precursor Protein (APP) by β and γ secretases, which aggregates more readily into fibrous structures and forms amyloid deposition plates that are more neurotoxic than aβ 1-40. Abeta 1-42 can be deposited between neuronal synapses to trigger activation of glial cells, release of free radicals and up-regulation of inflammatory factors, and finally induce apoptosis of neurons to form early biological events of AD. Thus, aβ 1-42 has an important role in AD diagnosis and pathogenesis studies. The onset of AD usually begins more than 10 years before the onset of clinical symptoms, during which there is a "cryptophase" or "preclinical phase" in which pathological changes have occurred but no significant cognitive impairment has occurred. If abnormal accumulation of aβ can be accurately detected at this stage, a valuable time window will be provided for intervention and treatment. Therefore, a detection technology which is high in sensitivity, low in cost, simple and convenient to operate and suitable for preclinical screening is developed, and the method has great social and medical values. The current mainstream AD detection technology has significant defects, such as 1) that cerebrospinal fluid detection needs invasive sampling, patient compliance is poor, and early screening is difficult to popularize, 2) that PET imaging depends on expensive equipment and radioactive tracking agents, and is high in cost, and is also difficult to popularize to early screening, and 3) that the traditional electrochemical/immunological method has insufficient sensitivity to low-concentration Abeta 1-42 (generally lower than 10 -9 M) in blood, and has the problems of complex operation and poor reproducibility. In recent years, the characteristics of high specific surface, excellent electron transmission performance, easy surface modification and the like of the silicon nanowire are widely applied to the design of a biosensor, however, the existing silicon nanowire needs to be grown at a high temperature of more than 400 ℃, is only suitable for high-temperature-resistant rigid substrates such as silicon wafers and the like, and cannot be compatible with a flexible and low-cost sensing platform. Although the screen-printed electrode is used as an ideal flexible sensing platform, the common polyimide substrate has an upper temperature resistance limit of about 250 ℃, and the high-temperature growth process of the silicon nanowires can lead to deformation failure of the substrate. Although some research attempts to achieve flexible integration by nanowire transfer processes, the transfer process is prone to interface belief, resulting in reduced signal stability and difficult control of manufacturing consistency. Therefore, it is of great importance to develop a technology that can grow silicon nanowires in situ at low temperature on Screen-printed carbon electrodes (Screen-Printed Carbon Electrodes, SPCE). Disclosure of Invention Aiming at the defects of the prior art, the invention provides a biosensor based on a screen printing electrode, a preparation method and application thereof, and solves the problems in the background art. In order to achieve the above purpose, the invention is realized by the following technical scheme: according to a first aspect of the present invention, there is provided a method for manufacturing a biosensor based on screen-printed electrodes, comprising the steps of: step 1, depositing a silicon film transition layer on the surface of a working electrode of a screen printing electrode by adopting PECVD equipment; step 2, spin-coating a tin dioxide solution on the surface of the silicon film transition layer to form