阅读说明：本技术 一种具有柔弹性的生物传感器及其应用 (Flexible and elastic biosensor and application thereof ) 是由 夏洪齐 章自寿 唐浩 周建华 李圆方 于 2019-09-27 设计创作，主要内容包括：本发明公开了一种具有柔弹性的生物传感器,包括工作电极；所述工作电极包括柔弹性导电复合膜基底,以及固定在柔弹性导电复合膜基底表面的酶；所述柔弹性导电复合膜基底由导电纳米体和柔弹性载体组成,本发明还公开了该生物传感器在制备可穿戴生物电子设备中的应用,可实现对生物电信号、生理生化信号的高灵敏采集,具有抗干扰能力强、灵敏度高、不需要外加媒介体等优点。(The invention discloses a biosensor with flexibility, which comprises a working electrode; the working electrode comprises a flexible elastic conductive composite film substrate and an enzyme fixed on the surface of the flexible elastic conductive composite film substrate; the invention also discloses application of the biosensor in preparation of wearable bioelectronic equipment, which can realize high-sensitivity acquisition of bioelectric signals and physiological and biochemical signals and has the advantages of strong anti-interference capability, high sensitivity, no need of an additional medium and the like.)

1. A flexible biosensor comprising a working electrode; the working electrode comprises a flexible elastic conductive composite film substrate and an enzyme fixed on the surface of the flexible elastic conductive composite film substrate; the flexible elastic conductive composite membrane substrate consists of a conductive nano body and a flexible elastic carrier.

2. The biosensor with flexibility according to claim 1, wherein the mass ratio of the conductive nanobody to the flexible carrier is 1: 9-9: 1.

3. The biosensor of claim 1, wherein the enzyme comprises one or more of horseradish peroxidase, glucose oxidase, lactate oxidase, alcohol oxidase, and cholesterol oxidase.

4. The biosensor having flexibility according to claim 1, wherein the material of the conductive nano-body includes one or more of gold nano-material, silver nano-material, and carbon nano-material.

5. The biosensor having flexibility according to claim 1, wherein the flexible carrier comprises ethylene-vinyl acetate copolymer, polydimethylsiloxane.

6. The flexible biosensor as claimed in claim 1, wherein the working electrode is prepared by the steps of:

s1, respectively and uniformly dispersing the conductive nano-bodies and the flexible elastic carriers in a good solvent, mixing and continuously performing ultrasonic treatment for 0.5-1 h to obtain conductive ink, and performing self-assembly to obtain a flexible elastic conductive composite film substrate;

s2, dripping 25-100 mu L of solution containing enzyme on the surface of the flexible and elastic conductive composite film substrate, standing for 1.5-2 h at 4-10 ℃, and fixing the enzyme on the surface of the flexible and elastic conductive composite film substrate after a crosslinking reaction to obtain the working electrode.

7. Use of a flexible biosensor in the manufacture of a wearable bioelectronic device, wherein the flexible biosensor is a flexible biosensor according to any one of claims 1-6.

8. Use of the flexible biosensor in the manufacture of a wearable device according to claim 7, wherein the wearable bioelectronic device is used for the acquisition of bioelectric signals, physiological and biochemical signals.

9. Use of a flexible biosensor as claimed in claim 8 in the manufacture of a wearable device, wherein the physiological and biochemical signals comprise glucose, lactate, ethanol and cholesterol concentrations.

Technical Field

The invention relates to the technical field of biosensors, in particular to a flexible biosensor and application thereof.

Background

With the improvement of the living standard of modern people and the aggravation of the aging problem of the population, the real-time detection and long-term monitoring technology of physiological and biochemical indexes of the human body is more and more widely concerned; the wearable biomedical sensing device is developed, physiological and biochemical signals of a human body are monitored in real time, and the wearable biomedical sensing device has important value and great demand in multiple fields of daily health management, health care, diagnosis and treatment rehabilitation and the like; although wearable devices have made some progress in monitoring vital signs of human bodies such as heart rate in recent years, generally, the current wearable sensors have single detection indexes, low detection efficiency and insufficient detection flux, and although high-flux detection can be realized by using the existing biochips, there are still many problems, such as high manufacturing cost of the biochips, additional arrangement of signal detection elements in the detection process, poor flexibility of the sensors, difficulty in making good contact with the skin and acquiring signals in real time, and the like.

Disclosure of Invention

The invention mainly aims to overcome the defects and provide a flexible biosensor and application thereof.

The technical scheme of the invention is as follows:

a biosensor having flexibility, comprising a working electrode; the working electrode comprises a flexible elastic conductive composite film substrate and an enzyme fixed on the surface of the flexible elastic conductive composite film substrate; the flexible elastic conductive composite membrane substrate consists of a conductive nano body and a flexible elastic carrier.

The conductive nano-body adopted by the invention has large specific surface area and excellent conductivity, and the flexible elastic carrier has excellent plasticity and can be made into various shapes, thereby effectively improving the conductivity, the ductility and the biocompatibility of the flexible elastic conductive composite film.

Furthermore, the mass ratio of the conductive nano-bodies to the flexible elastic carrier is 1: 9-9: 1, and the flexibility and the conductivity of the flexible elastic conductive composite film can be adjusted according to the mass ratio of the conductive nano-bodies to the flexible elastic carrier.

Further, the enzyme comprises more than one of horseradish peroxidase, glucose oxidase, lactate oxidase, alcohol oxidase and cholesterol oxidase.

Further, the material of the conductive nano-body comprises more than one of gold nano-material, silver nano-material and carbon nano-material.

Further, the flexible carrier comprises ethylene-vinyl acetate copolymer and polydimethylsiloxane.

Further, the working electrode is prepared by adopting the following steps:

s1, respectively and uniformly dispersing the conductive nano-bodies and the flexible elastic carriers in a good solvent, mixing and continuously performing ultrasonic treatment for 0.5-1 h to obtain conductive ink, and performing self-assembly to obtain a flexible elastic conductive composite film substrate;

s2, dripping 25-100 mu L of solution containing enzyme on the surface of the flexible and elastic conductive composite film substrate, standing for 1.5-2 h at 4-10 ℃, and fixing the enzyme on the surface of the flexible and elastic conductive composite film substrate after a crosslinking reaction to obtain the working electrode.

Among them, xylene and cyclohexane are commonly used as good solvents.

The substrate of the flexible elastic conductive composite membrane has good biocompatibility and can effectively keep the bioactivity of immobilized enzyme.

The invention also provides application of the biosensor with flexibility in preparation of wearable bioelectronic equipment.

Further, the wearable bioelectronic device is applied to acquisition of bioelectric signals and physiological and biochemical signals.

Further, the physiological and biochemical signals include glucose concentration, lactic acid concentration, ethanol concentration and cholesterol concentration.

The biosensor with flexibility provided by the invention adopts a three-electrode system (comprising a working electrode, a counter electrode and a reference electrode) or a two-electrode system (comprising the working electrode and the counter electrode). The counter electrode adopts a platinum electrode or a carbon electrode, but not limited to, and the reference electrode adopts an Ag/AgCl electrode or a saturated calomel electrode.

The working principle of the biosensor with flexibility provided by the invention is as follows: the biological enzyme fixed on the surface of the flexible elastic conductive composite membrane substrate and a substrate to be detected are subjected to catalytic reaction, electron transfer exists in the process, so that the current of an electrode system is changed, the higher the concentration of the substrate to be detected is, the higher the current is, and the concentration of the substrate to be detected can be indirectly calculated by detecting the variable quantity of the current.

The biosensor with flexibility provided by the invention can be used for detecting a substrate which can be specifically catalyzed by enzyme fixed on the surface of the substrate of the flexible and elastic conductive composite membrane, for example, horseradish peroxidase is fixed on the surface of the substrate of the flexible and elastic conductive composite membrane, and the substrate which can be catalyzed is hydrogen peroxide, so that the biosensor can be applied to detecting the concentration of the hydrogen peroxide; if the glucose oxidase and the horseradish peroxidase are fixed on the surface of the substrate of the flexible elastic conductive composite membrane together, and the substrate capable of catalyzing is glucose, the biosensor can be applied to detecting the concentration of the glucose; the biosensor with flexibility of the invention can fix enzymes including, but not limited to, horseradish peroxidase, glucose oxidase, lactate oxidase, alcohol oxidase and cholesterol oxidase.

Compared with the prior art, the invention has the following advantages:

1. the flexible elastic conductive composite membrane is prepared by mutually winding and self-assembling the conductive nano-body and the flexible elastic carrier through hydrophobic interaction at room temperature, the surface of the flexible elastic conductive composite membrane is a compact and uniform three-dimensional porous structure and has higher conductivity, the conductivity of the flexible elastic composite membrane is measured through a linear sweep voltammetry, the flexibility of the flexible elastic composite membrane is characterized through bending, folding, twisting, knotting and the like, and the flexible elastic composite membrane is cut into flexible elastic electrodes, so that the high-sensitivity acquisition of biological electric signals (such as myoelectric signals) can be realized, and the flexible elastic composite membrane has the characteristics of low cost, easiness in processing and the like, and is easy for industrial production.

2. The invention adopts the flexible elastic conductive composite membrane prepared by conductive nano-body and flexible elastic carrier, takes the flexible elastic conductive composite membrane as a substrate, adsorbs and fixes enzyme on the surface of the substrate through cross-linking reaction, and generates direct electron transfer, thereby realizing the direct high-sensitivity acquisition of physiological and biochemical signals, having simple detection method and no need of markingStrong recording and anti-interference ability, high sensitivity (for example, in the detection of hydrogen peroxide, its linear sensitivity can be up to 2 mA mM in the concentration range of 0.1 mM-1 mM^-1cm^-2The response time is 2-3 s), no additional medium is needed, and the like, and the method can be used for preparing wearable bioelectronic equipment and can be widely applied to the fields of biomedical detection, health monitoring, environmental early warning and the like.

Drawings

FIG. 1 is a Scanning Electron Microscope (SEM) photograph of a flexible and elastic carbon nanotube composite film according to the present invention;

FIG. 2 is an image of the present invention using a flexible carbon nanotube composite membrane for collecting electromyographic signals;

FIG. 3 is a time-current response (A) and a detection curve (B) of the biosensor having flexibility according to the present invention when a 0.1 mM hydrogen peroxide solution is continuously added;

FIG. 4 is a time-current response (A) and a detection curve (B) of the biosensor having flexibility according to the present invention when a 0.1 mM glucose solution is continuously added;

FIG. 5 is a time-current response (A) and a detection curve (B) of the flexible biosensor of the present invention for glucose concentration detection in sweat;

the implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, will make the advantages and features of the invention easier to understand for those skilled in the art and will therefore make the scope of the invention more clearly defined.