Preparation method of electrochemical sensor with surface curing polypeptide probe

Abstract

The invention discloses a preparation method of an electrochemical sensor with a surface curing polypeptide probe. The method comprises the following steps that electrodes of the electrochemical sensor are prepared on a base material; oxidized dopamine is utilized for cross-linking metal nanometer particles and polypeptide probe molecules, and the cross-linked metal nanometer particles and polypeptide probe molecules are attached to a working electrode, that is to say, a polydopamine probe layer is formed on the working electrode; a permeable membrane solution is plated to the polydopamine probe layer and dried, and a permeable membrane solution is formed. According to the preparation method of the electrochemical sensor with the surface curing polypeptide probe, the multiple purposes such as electrode modification, polypeptide probe molecule curing and bonding layer adding are achieved in the same process simultaneously through a dopamine oxidation polymerization reaction, the manufacturing process is greatly simplified, and the manufacturing cost is reduced. Dopamine has good biocompatibility, achieves an excellent adhesive effect and can be closely boned to almost all types of surfaces. Therefore, for the manufacturing process, the step of adding biocompatibility adhesives or conducting bonding treatment after permeable membrane coating can be omitted, the production process is simplified, and the cost is reduced.

Description

technical field [0001] The invention relates to the technical field of electrochemical sensors, in particular to a method for preparing an electrochemical sensor with a surface-cured polypeptide probe. Background technique [0002] An electrochemical sensor is a sensor that detects the content or concentration of a target analyte in a sample with an electrochemical signal, which is generated by a change in Faradaic current or a change in properties such as AC impedance. Generally, an electrochemical sensor is composed of at least one working electrode, a counter electrode and a reference electrode, and the working electrode has probe molecules that can bind or chemically react with the target analyte in the detection sample. [0003] Currently available probe molecules include ribonucleic acid chains, enzymes, polypeptide antibodies or other proteins that can bind to analytes, etc. Among them, proteins such as enzymes and antibodies can be collectively referred to as polypep...

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Problems solved by technology

[0005] There are deficiencies in the existing curing processes of various probe molecules, which are mainly reflected in: the peptide cross-linking process usually uses glutaraldehyde as a cross-linking medium to promote covalent cross-linking between polypeptide molecules and adjacent molecules. It will change the third-order and fourth-order structures of polypeptides, significantly reducing the activity and sensitivity of probe molecules, especially enzyme molecules; and glutaraldehyde is an extremely flammable and volatile toxic substance, which is not conducive to safe production in large quantities

Its disadvantage is that it has extremely high requirements on the flatness of the metal electrode surface, and can only achieve single-layer curing, so the molecular density of the cured probe is low, and the sensitivity performance of the sensor is poor.

The disadvantage is that most photosensitive adhesives have certain biological toxicity, which is not suitable for use in in vivo sensors, and the precision ultraviolet exposure equipment is expensive, and the development process is more complicated, making its manufacturing cost higher

Among them, the glue layer needs to meet the two requirements of biocompatibility and the ability to bond two layers of substances with completely different physical and chemical properties, so the options are very limited, and often need to be developed separately according to the specific properties of the probe molecular layer and the permeable membrane layer. lead to high manufacturing costs

In the chemical reaction process, due to the high sensitivity of the polypeptide probe molecules to reaction conditions such as temperature, pH of the solution, and organic or corrosive solvents, in order to ensure that the probe molecules will not be destroyed, the practical chemical reaction options are also very limited.

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