阅读说明：本技术 一种超高灵敏度多巴胺生物传感器及其制备方法 (Ultra-high-sensitivity dopamine biosensor and preparation method thereof ) 是由 李爱东 A·丹尼尔·阿鲁拉杰 任强 吴迪 于 2020-06-22 设计创作，主要内容包括：本发明公开了一种超高灵敏度多巴胺生物传感器及其制备方法,属于生物传感器领域,实现了对多巴胺的快速电化学响应,具有低至0.4pM的检测限,优异选择性,且工艺简单、成本低廉,适合临床诊断和生理功能检测,特别是活体多巴胺静态基础值的测定。本发明的多巴胺生物传感器包括从上至下依次为HfO<Sub>2</Sub>超薄膜、导电硅衬底、Al电极；采用与半导体工艺兼容的热ALD或等离子体增强ALD在导电硅基底上低温沉积HfO<Sub>2</Sub>超薄膜；再在硅衬底背面蒸镀金属铝以形成良好的电学接触,即获得了多巴胺生物传感器。(The invention discloses an ultrahigh-sensitivity dopamine biosensor and a preparation method thereof, belongs to the field of biosensors, realizes quick electrochemical response to dopamine, has a detection limit as low as 0.4pM, excellent selectivity, simple process and low cost, and is suitable for clinical diagnosis and physiological function detection, particularly for measuring a static basic value of living dopamine. The dopamine biosensor comprises HfO sequentially arranged from top to bottom 2 Ultra-thin film, conductiveA silicon substrate, an Al electrode; low temperature deposition of HfO on a conductive silicon substrate using thermal ALD or plasma enhanced ALD compatible with semiconductor processes 2 An ultrathin film; and evaporating metal aluminum on the back of the silicon substrate to form good electrical contact, thus obtaining the dopamine biosensor.)

1. An ultra-high sensitivity dopamine biosensor, comprising: the sensor comprises a conductive substrate and a sensitive layer, wherein the sensitive layer is positioned on the upper layer of the conductive substrate.

2. The ultra-high sensitivity dopamine biosensor of claim 1, wherein the sensor further comprises a metal aluminum layer; the metal aluminum layer is positioned on the lower layer of the conductive substrate.

3. The dopamine biosensor as claimed in claim 1 or 2, wherein the conductive substrate is a conductive silicon substrate, and the sensitive layer is HfO₂An ultra-thin film.

4. The ultra-high sensitivity dopamine biosensor of claim 3, wherein the HfO is₂The thickness of the ultrathin film is 15-40 nanometers.

5. A preparation method of an ultrahigh-sensitivity dopamine biosensor is characterized by comprising the following steps:

on a conductive silicon substrate, adoptLow temperature deposition of HfO at 80-350 ℃ using thermal ALD or plasma-enhanced ALD (PEALD) compatible with semiconductor processes₂An ultrathin film; and evaporating metal aluminum on the back of the silicon substrate to obtain the dopamine biosensor.

6. The method of claim 5, wherein the HfO is selected from the group consisting of a polymer, and a metal oxide₂The thickness of the ultrathin film is 15-40 nanometers.

7. The method for preparing the ultra-high sensitivity dopamine biosensor according to claim 5, wherein the thermal ALD deposition parameters are: the hafnium source is an organic hafnium source or an inorganic hafnium source, the oxygen source is water, and the cycle number is 150-400 cycles.

8. The method for preparing the ultra-high sensitivity dopamine biosensor according to claim 5, wherein the deposition parameters of the plasma enhanced ALD are as follows: the hafnium source is an organic hafnium source or an inorganic hafnium source, the oxygen source is oxygen plasma, and the cycle number is 150-400 cycles.

9. The method for preparing the dopamine biosensor having ultrahigh sensitivity according to claim 7 or 8, wherein the organic hafnium source is hafnium dimethylamide or hafnium dimethylaminoethyl amide, and the inorganic hafnium source is hafnium tetrachloride.

Technical Field

The invention belongs to the field of biosensors, and particularly relates to an ultrahigh-sensitivity dopamine biosensor and a preparation method thereof.

Background

Dopamine (3, 4-dihydroxyphenylethylamine) is an important neurotransmission substance in human body, and plays a key role in the aspects of memory, emotional activity and pressure of brain, movement of human body and the like in central nervous system and endocrine system. Abnormal dopamine levels are closely related to various nervous system diseases such as Parkinson's disease, Alzheimer's disease, depression, schizophrenia, renal failure and heart failure. And dopamine is used as an adrenomimetic drug and is widely used for treating diseases such as nervous disorder, congenital cardiovascular and hypertension, even depression and the like. Therefore, the development of a dopamine content determination method has important practical significance in both clinical application and physiological function research.

At present, dopamine neurotransmitter analysis methods are various, such as electrochemical analysis methods, spectrophotometry, liquid chromatography, fluorescence spectroscopy, titration methods and the like, and compared with other detection methods, the electrochemical analysis methods have the advantages of good stability, high sensitivity, high selectivity, convenience in use, low cost and the like, can perform online real-time detection, and are extremely competitive and attractive test methods. Although the dopamine electrochemical sensor has certain advantages, the dopamine electrochemical sensor still faces the challenge of detection limit (LoD), and when the concentration of dopamine is reduced to be ultra-low to 1pM, most of the electrochemical sensors cannot meet the detection requirement. Also, many electrochemical sensors require the introduction of binders (binders) in the electrode preparation for improved stability and sensitivity, which reduces the selectivity of the sensor. Therefore, by introducing a new material, a new structure and a new process, the development of a novel ultra-sensitive high-selectivity dopamine electrochemical sensor has important significance.

The Atomic Layer Deposition (ALD) method is a new and rapidly developing material preparation technology. The potential for ALD technology development has been strong since 2001, the International society for the semiconductor Industry (ITRS), juxtaposed ALD with Metal Organic Chemical Vapor Deposition (MOCVD), plasma enhanced CVD as candidates compatible with microelectronic processes. The atomic layer deposition is a method for forming a thin film by alternately introducing gas-phase precursor pulses into a reactor and performing a chemical adsorption reaction on the surface of a deposition substrate, and the unique self-limiting and self-saturation reaction mechanism ensures large-area uniformity, excellent three-dimensional conformality and precise controllability (angstrom scale) of the thickness of the deposited thin film, and particularly shows outstanding advantages in the aspects of surface modification and interface modification of materials. In recent years, atomic layer deposition has shown wide application prospects in the fields of microelectronics, optoelectronics, nanotechnology, new energy, catalysis, biomedicine and the like. However, the application of ALD to the field of biosensors is relatively rare, and particularly, the application to the preparation of ultra-high sensitivity dopamine biosensors is extremely deficient.

Disclosure of Invention

The invention provides an ultra-high sensitivity dopamine biosensor and a preparation method thereof, and ultra-thin HfO is deposited on a commercial conductive silicon substrate by ALD₂The film is used as a sensitive layer, realizes quick electrochemical response to dopamine, has a detection limit as low as 0.4pM, excellent selectivity, simple process and low cost, and is suitable for clinical diagnosis and physiological function detection, especially for measuring the static basic value of living dopamine.

In order to achieve the purpose, the invention adopts the following technical scheme:

an ultra-high sensitivity dopamine biosensor comprising: the sensor comprises a conductive substrate and a sensitive layer, wherein the sensitive layer is positioned on the upper layer of the conductive substrate.

In the above structure, the sensor further comprises a metal aluminum layer; the metal aluminum layer is positioned at the lower layer of the conductive substrate, the conductive substrate is a conductive silicon substrate, and the sensitive layer is HfO₂Ultra-thin film of said HfO₂The thickness of the ultrathin film is 15-40 nanometers.

A preparation method of an ultrahigh-sensitivity dopamine biosensor comprises the following steps:

on a conductive silicon substrate, thermal ALD or plasma-enhanced ALD (plasma-enhanced ALD) compatible with semiconductor process is employedced ALD, PEALD) low temperature deposition of HfO₂An ultrathin film; and evaporating metal aluminum on the back of the silicon substrate to obtain the dopamine biosensor.

In the above step, the low-temperature deposition temperature is 80-350 ℃, and the HfO₂The thickness of the ultrathin film is 15-40 nanometers; the deposition parameters of thermal ALD are: the hafnium source is an organic hafnium source or an inorganic hafnium source, the oxygen source is water, and the cycle number is 150-400 cycles; the deposition parameters of plasma enhanced ALD are: the hafnium source is an organic hafnium source or an inorganic hafnium source, the oxygen source is oxygen plasma, and the cycle number is 150-400 cycles; the organic hafnium source is dimethyl amino hafnium or dimethyl ethyl amino hafnium, and the inorganic hafnium source is hafnium tetrachloride.

Has the advantages that: the invention provides an ultrahigh-sensitivity dopamine biosensor, a preparation method thereof and prepared HfO₂the/Si-based dopamine biosensor is a binder-free electrochemical sensor, has the advantages of high sensitivity (as low as the detection limit of 0.4 pM), quick response (3s), high stability and high repeatability, also shows excellent selectivity, is simple in process and low in cost, is suitable for clinical diagnosis and physiological function detection, particularly for measuring the static basic value of living dopamine, and has important application prospects in the field of ultrahigh-sensitivity dopamine detection.

Drawings

FIG. 1 is a schematic structural diagram of an ultra-high sensitivity dopamine biosensor in an embodiment of the invention;

FIG. 2 shows an ALD deposition on a conductive silicon substrate of 200 cycles of HfO in an embodiment of the present invention₂A thin film Scanning Electron Microscope (SEM) photograph;

FIG. 3 shows an ALD deposition on a conductive silicon substrate of 200 cycles of HfO in an embodiment of the present invention₂XPS spectra of films: hf 4f and O1 s;

FIG. 4 shows 200 cycles HfO in an embodiment of the present invention₂CV scan curves of conductive silicon substrate as working electrode at different scan rates in 0.1M PBS (pH 7) solution containing 50 μ M dopamine;

FIG. 5 shows 200 cycles HfO in an embodiment of the present invention₂Conductive Si substrate for different concentrations of dopamineDPV response (a) for 0.1M PBS (pH 7) solution and fitted calibration curves (b) and (c) plots;

fig. 6 is a graph of DPV response (a) and fitted calibration curve (b) for reference sample conductive Si substrates to 0.1M PBS (pH 7) solutions of varying concentrations of dopamine in an example of the invention;

FIG. 7 is a diagram of 200 cycles HfO in an example embodiment of the present invention₂Conductive silicon substrate polybara sensor selectivity and interference test: (a) 200 cycle HfO in contrast to dopamine₂CV response curves of other biomolecules in 0.1M PBS solution for conductive silicon substrates, (b) 200-cycle HfO in the presence of several interfering species₂A DPV interference response test result graph of the conductive silicon substrate;

FIG. 8 shows 200 cycles HfO in an embodiment of the present invention₂Conducting silicon substrate base dopamine sensor repeatability tests, wherein the dopamine concentration is 300pM, and the DPV curve comprises 17 times of scanning;

FIG. 9 shows 300 cycles HfO in an embodiment of the present invention₂DPV response of conductive Si substrate to 0.1M PBS (pH 7) solutions of different concentrations of dopamine (a) and fitted calibration curves (b) and (c) plots;

FIG. 10 shows an exemplary 400-cycle HfO process₂DPV response of/conductive Si substrates to 0.1M PBS (pH 7) solutions of different concentrations of dopamine (a) and fitted calibration curves (b) and (c) plots.

Detailed Description

The invention is described in detail below with reference to the following figures and specific examples: