A kind of potassium ion biochemical analysis dry plate and preparation method thereofTechnical field
The present invention relates to vim and vigour biochemical sensor technologies field, particularly relate to a kind of potassium ion biochemical analysis dry plate and preparation method thereof.
Background technology
Human body fluid electrolyte concentration is clinical examination, treatment is assessed and the important evidence of Index for diagnosis.As one of important kation of human body fluid, potassium ion has acid base equilibrium in control agent, maintains muscle, neural irritability, participates in the vital role such as the anabolism of intracellular matter.In actual clinical work, conventional serum potassium concentration reacts the level of potassium in human body body.The equipment of measurement potassium concentration conventional is at present the wet type biochemical analysis detector relying on ion-selective electrode principle.
Traditional wet type biochemical analysis detect have that complicated operation, operation and maintenance cost are high, low-response, the shortcoming such as not portable.Novel electrolyte detection method---dry type detects, and has and measures the features such as accurate, with low cost, simple to operate, can be widely used in multiple environment.
Chinese patent CN101871912A discloses a kind of full-solid potassium ion sensor and preparation method thereof, comprises reaction electrode, contact electrode, wire, reference layer, ion-selective membrane, insulation course.Chinese patent CN12636532A discloses a kind of medical type all-solid potassium ion selectivity sensor and preparation method thereof, and eliminate solid electrolyte reference layer, the long-time stability of the test result of above-mentioned patent and response time all also need further improvement.
Existing patent adopts screen printing technique to prepare electrode substantially, but the metal level purity that serigraphy obtains is inadequate, and surface is uneven, can affect stability and the response time of electromotive force; And in existing solid ionic choice electrode, all select Polyvinylchloride as the high polymer binder (patent CN101852761A, CN104330449A, CN102636532A, CN101871912A, CN102558724A etc.) of ion-selective membrane, Polyvinylchloride has higher intensity and chemical stability, low price, but it must add plastifier just can guarantee that ion-selective membrane responds, As time goes on, plastifier be dissolved in carrier wherein can together with leak out from ion-selective membrane, cause ion-selective membrane to respond lower limit to be deteriorated, lifetime.
Summary of the invention
For existing potassium ion-selective electrode Problems existing, the invention provides a kind of potassium ion biochemical analysis dry plate and preparation method thereof, prepared dry plate measuring accuracy is high, long-time stability are good, response time is short, and structure is simple, volume is little, preparation technology is simple, production cost is low, is applicable to producing in enormous quantities.
Potassium ion biochemical analysis dry plate of the present invention comprises supporting layer, insulation course, salt bridge, electrode, reference layer and potassium ion selective membrane.Preparation technology is as follows: (1) prepares metal/metal salt thin electrode; (2) on electrode, the reference layer solution prepared and potassium ion selective membrane solution is coated with and potassium ion-selective electrode is prepared in drying; (3) convince pore by patient analysis on the insulating layer, salt bridge is sealed in insulation course; (4) by two panels potassium ion-selective electrode and supporting layer, the bonding assembling dry plate of insulation course.
In the present invention, supporting layer plays protection, supports potassium ion-selective electrode effect, and insulation course plays bonding electrode, the effect of sealing salt bridge, and salt bridge plays the effect of connection electrode; Insulation course has gas port, the flow rate of reference liquid and test fluid during test, can be improved, shorten the test duration; Supporting layer, insulation course are selected from polypropylene, Polyvinylchloride, tygon, polyester non-conductive polymer material, and salt bridge is filter paper material.
Electrode.Electrode of the present invention comprises metal level and metal salt.Metal salt and metal level form phase boundary potential, have stable electromotive force response.Metal is selected from gold, silver, copper, mercury, platinum, nickel, and slaine is selected from the insoluble metallic salt of metal level metal.Metal salt can use the oxide of metal level metal, such as metal halide.Preferred electrode is silver/silver chloride electrode.
Electrode metal layer is attached to non-conductive polymer surface, be improve electrode stability, shorten the response time, the present invention can adopt vacuum coating, the mode of electroless plating or plating prepares metal level, preferred electroless plating method.Use electroless plating method, layer on surface of metal is even, can set up the balance between phase boundary instantaneously, form stable response electromotive force, shortens the response time.Metal salt can adopt the method for chemical oxidation to obtain, and uses iron chloride or liquor potassic permanganate to be oxidized metal level.
Reference layer.Reference composition of layer comprises: cementing agent, slaine, surfactant.Reference layer is directly attached on electrode metal salt deposit by the mode of lamination or coating.
Need in reference layer used herein containing the identical negative ion of electrode metal salt deposit and kation potassium ion to be measured.As requested, in reference layer, slaine potassium chloride can be selected, but potassium chloride solubleness temperature influence is comparatively large, preferable alloy salt sodium chloride and potassium chloride composite.The proportioning of sodium chloride and potassium chloride directly can affect and respond potential stability, and the bonding strength of reference layer and potassium ion selective membrane can be affected, the stability of response can be improved by the proportioning changing sodium chloride and potassium chloride, the proportioning of preferred sodium chloride and potassium chloride is 5:1, and slaine accounts for 20% ~ 50% of reference layer gross mass.
Reference layer binder is selected from one or more in gelatin, agar, polyacrylamide, polyvinyl alcohol (PVA) or other polyvinyl, accounts for 30% ~ 80% of reference layer gross mass.
For ensureing the bond strength of reference layer and potassium ion selective membrane, prevent potassium ion biochemical analysis dry plate response signal accuracy and long-time stability from reducing, reference layer water cut can not be too high or too low, and reference layer optimum moisture content is 30% ~ 40%.
The present invention by controlling drying time of reference layer, temperature, humidity fixes sodium chloride and potassium chloride proportioning and water cut in reference layer, preferred drying condition: temperature 25 DEG C, relative humidity 50%, time 40min.
Potassium ion selective membrane.Potassium ion selective membrane composition comprises: high polymer binder, ionophore, carrier solvent, negative ion agent interfering, surfactant.
Carrier solvent requires energy dissolved ions carrier, and has good compatibility with high polymer binder, guarantees that carrier moves in high polymer binder.Usual carrier solvent can be used as macromolecular material plastifier and uses, and is selected from one or more in phthalic ester, sebacate, ortho-nitrophenyl octyl ether, adipate mixing aromatic aliphatic phosphate, accounts for 30% ~ 70% of potassium ion selective membrane gross mass.
For reducing the consumption of plastifier, reduce carrier and run off, promote the long-time stability of potassium ion selective membrane, the high polymer binder that the present invention uses is hydroxyvinyl resinous material.In hydroxyvinyl resin, hydroxyl can increase the water wettability of ion-selective membrane, can shorten the response time of electrode, improves the stability of electrode response.Hydroxyvinyl resin side chain is conducive to reducing intermolecular force, reduces the use of plastifier, reduces carrier and runs off, and increases sensing range and the life-span of ion-selective membrane.Hydroxyvinyl resin is selected from one or more in the polyvinyl of vinyl chloride, vinyl acetate and vinyl alcohol three kinds of structural units, optimization polyurethane-vinyl chloride-vinyl acetate resin, accounts for 15% ~ 40% of potassium ion selective membrane gross mass.。
Negative ion agent interfering can get rid of lipophilic anion in liquid to be measured (as long-chain fatty acid, long chain alkyl sulphonates or long-chain Acidic phosphates salt etc.) to ionophoric interference, improve the sensitivity of electrode pair cation selective, expand the linear response range of ion-selective electrode.Be selected from one or more in potassium tetraphenylborate, potassium tetraphenylborate, four (4-chlorphenyl) potassium borate, four [two (trifluoromethyl) phenyl of 3,5-] potassium borate, account for 0.5% ~ 2% of potassium ion selective membrane gross mass.
Ionophore selects compound potassium ion to selective response, carrier is selected from valinomycins, two [(benzene-15-crown ether-4)-4 '-methyl] pimelate, 2-dodecane-2-methyl isophthalic acid, 3-glyceryl is two, and [N-(5 '-nitro (benzene-15-crown ether-5)-4 '-Ji) carbamate, dibenzo-18-crown-6 (DB18C6), bicyclohexane one in 24-crown ether-8, account for 1% ~ 5% of potassium ion selective membrane gross mass.
Surfactant is selected from one or more in organosilicon or siloxane type surfactants, accounts for 0.1% ~ 3% of potassium ion selective membrane gross mass.
Be different from potassium ion-selective electrode in existing patent, major advantage of the present invention has: (1) eliminates liquid electrolyte layer, adopts structure of whole solid state, convenient and swift, does not need long-time activation during use; (2) by potassium chloride in adjustment reference layer and potassium chloride proportioning, fixing reference layer water cut, and use the high polymer binder that hydroxyvinyl resin is potassium ion selective membrane, promote measuring accuracy and the long-time stability of potassium ion biochemical analysis dry plate; (3) the metal/metal salt thin electrode surface uniform prepared, shortens the potassium ion biochemical analysis dry plate response time greatly, can equilibrium establishment within 7s, forms stable response electromotive force; (4) structure is simple, volume is little, and size is 10mm × 10mm, is easy to integrated, can be developed into superminiature biochemical analysis dry plate, and preparation technology is simple, with low cost, is suitable for large-scale industrial production.
Accompanying drawing explanation
Fig. 1 is potassium ion biochemical analysis dry plate schematic diagram.
Fig. 2 is potassium ion-selective electrode (electrode, reference layer, ion-selective membrane) schematic diagram.
Fig. 3 is potassium ion biochemical analysis dry plate testing standard liquid response potential curve.
Fig. 4 is potassium ion selective membrane test variable concentrations KNO3solution response electromotive force.
Fig. 5 is potassium ion biochemical analysis dry plate family curve.
Fig. 6 is potassium ion biochemical analysis dry plate long term stability tests result.
Embodiment
The present invention is described in detail with embodiment by reference to the accompanying drawings.
As shown in Figure 1, potassium ion biochemical analysis dry plate comprises: supporting layer 1, potassium ion-selective electrode 2, insulation course 3, salt bridge 4.
As shown in Figure 2, potassium ion-selective electrode comprises: silver layer 21, silver chloride layer 22, reference layer 23, potassium ion selective membrane 24.
Concrete implementation step is as follows.
By the method for electroless plating at polyethylene terephthalate plated surface silver layer, prepare silver layer 21.
Chemical method is adopted to be oxidized by front for silver layer 21 2/3 section.The contact electrode being oxidized position will be needed to be immersed in 0.1mol/L ferric chloride solution after 60s, and taking-up pure water cleans up and drying, obtains silver chloride layer 22.
Reference layer is coated with.By 6g polyvinyl alcohol (PVA), 1g glycerine, 5g potassium chloride, 1g potassium chloride, 0.02g germifuge, 0.004g surfactant H212 is dissolved in 100g water, is coated on silver chloride layer 22, and at 25 DEG C, dry 60min under relative humidity 50% environment.
Potassium ion selective membrane is coated with.By 0.1g polyurethane-vinyl chloride-vinyl acetate resin, 0.15g ortho-nitrophenyl octyl ether, two [(benzene-15-crown ether-4)-4 '-methyl] pimelate of 0.006g, 0.005g potassium tetraphenylborate, 0.005g surfactant H212 is dissolved in acetone, is coated on reference layer 23, and drying at room temperature.
After potassium ion selective membrane 24 drying, get two panels potassium ion-selective electrode 2 bonding with insulation course 3, by bonding with supporting layer 1 for insulation course 3 assembling dry plate after solidification.
Potassium ion biochemical analysis dry plate long-term storage conditions is :-18 ~-10 DEG C.
Potassium ion biochemical analysis dry plate using method, uses after needing to place 1h at normal temperatures when taking out from low temperature environment, keeps probe temperature 37 ± 0.1 DEG C during test.During test, dry plate is inserted in test trough, two lateral opening dropping reference liquid and test fluid respectively, required sample 5 ~ 10 μ L.
In order to advantage of the present invention is better described, the invention provides 4 groups of experimental datas, specific as follows.
Experiment 1, with potassium ion biochemical analysis dry plate testing standard liquid, response electromotive force and the curve of test duration are as shown in Figure 3.
Experiment 2, prepares potassium ion selective membrane test variable concentrations KNO3solution (0.001mol/L, 0.004mol/L, 0.07mol/L) responds electromotive force, and test result as shown in Figure 4.
Experiment 3, calibrates potassium ion biochemical analysis dry plate.By known potassium concentration titer (potassium concentration 2mmol/L and 11mmol/L), test potassium ion biochemical analysis dry plate response electromotive force, obtains electromotive force response corrections curve.Correction equation is: Y=61.2X+103.34, and wherein Y represents response electromotive force, and X represents logC, and C is potassium concentration in solution.Family curve as shown in Figure 5.
Experiment 4, potassium ion biochemical analysis dry plate long term stability tests, with the response electromotive force of measurement standard liquid (potassium concentration 2mmol/L) respectively in the potassium ion biochemical analysis dry plate 90 days of a collection of preparation, test result as shown in Figure 6.
The above its object is to person skilled in the art can be understood content of the present invention and implement according to this only for technical conceive of the present invention and feature are described, can not limit the scope of the invention with this.All modifications done according to the Spirit Essence of main technical schemes of the present invention, all should be encompassed within protection scope of the present invention.