Galvanochemistry ultramicroelectrode combined method and ultra-micro compound electrode thereof and preparation technology
[technical field]
The present invention relates to Electroanalytical Chemistry, biosensor technology field, be specifically related to a kind of ultramicroelectrode combined method and ultra-micro compound electrode structure of making according to this method and the process of making this electrode.
[background technology]
Cell is biological elementary cell, is the starting point of evolving, and is the basic object that life science must be familiar with.The new technology of surveying in the developing cells is to the dopamine in single cynapse, the vesica in individual cells and the cell (Dopamine, neurotransmitter, nitrogen monoxide (NO), hydrogen peroxide (H such as DA)
2O
2) and informational molecule such as oxygen radical carry out at body, real-time and dynamic chemical probing, be that analytical chemistry has challenging advanced subject, also be the important point of penetration of further investigation brain and nervous function.
The detection technique of neurotransmitter and informational molecule has obtained extensive studies in the cell, wherein fluorescence histochemical method and immunohistological method can only the indirect determination neurotransmitters, for some active height, short, the then very difficult mensuration of extremely unsettled free radical of life-span, more can't carry out real-time detection the in the born of the same parents.The galvanochemistry voltammetry has the characteristic of time resolution and spatial discrimination, at body, in real time, performance analysis provides necessary base, becomes the main method of research nervous centralis activity.The application power of voltammetry depends on the sweep speed upper limit, sweep velocity or frequency are high more, its the dynamics time window that can differentiate just extends to low side more, just can study the fast more out-phase electron transfer process and the homogeneous chemistry process of coupling thereof, follow the trail of short-life more intermediate, expand understanding greatly electron transfer and Chemical Kinetics.Because solution resistance R in the physiology system
sBe far longer than the resistance of ideal system, available the sweep speed of ultrafast voltammetry in physiological environment seldom surpasses several kV/s, is far smaller than the highest speed of sweeping in the ideal system.Though R
sCan compensate by positive feedback technique, but R
sBig more, the feedback resistance of use and compensating resistance are also big more, cause instrument and circuit bandwidth to reduce, and make it finally can not be used for ultrafast volt-ampere analysis.Volt-ampere is surveyed in the conventional cell, be that the ultra micro working electrode is inserted in the cell to be measured, place the extracellular to make it not influence operation at a distance to electrode and contrast electrode, this detection method is crossed over cell membrane, not only solution resistance is bigger, the stimulation of pair cell system and disturbance are also very big, directly influence the confidence level and the sensitivity of measurement result.
At present common working electrode volume is bigger, disturbance, damage to system to be measured are bigger, can't in studying, live body, on-the-spot ultrafast volt-ampere set up the electrode system of a low solution resistance, caused the reduction of instrument and circuit bandwidth like this, make the sensitivity that detects reduce, and finally have influence on the confidence level of testing result.Patent Office of the People's Republic of China discloses a kind of preparation technology's (application number: 03137469.7) of compound microelectrode, a kind of method that it provides the miniature reference electrodes in a kind of compound microelectrode to make, it is to adopt glass capillary that micron-sized filamentary silver, platinum filament and carbon fiber are encapsulated in the thin metal pipe inner chamber through insulation, wherein, seal with the solid paraffin fusing at carbon fiber electrode glass capillary two ends; Miniature silver/silver chloride (Ag/AgCl) miniature reference electrodes is utilized the capillarity of glass capillary, seals the saturated potassium chloride solution of one section saturated silver chloride in kapillary up for safekeeping; Platinum filament seals the solid paraffin of electrode glass kapillary two ends with fusing.But, said method adopts three grades of electrode systems, the compound microelectrode that obtains according to this method also only is to provide more stable reference potential by miniature reference electrodes in cell measurement, though improved the degree of accuracy of measuring to a certain extent, prepared compound microelectrode can't adapt to, satisfy neurotransmitter, nitrogen monoxide (NO), hydrogen peroxide (H
2O
2) and multiple informational molecule such as oxygen radical carry out in body, real-time and dynamic chemical probing requirement.
Therefore, in carrying out live body, on-the-spot ultrafast volt-ampere research, set up the novel microelectrode system of a low solution resistance, reduce the interference of pair cell vital movement, to improve available speed and the detection sensitivity of sweeping in the actual analysis environment, very necessary and important.
[summary of the invention]
Technical matters to be solved by this invention is to overcome above-mentioned existing ordinary electrode system to exist solution resistance bigger in detecting, the stimulation of pair cell system and disturbance be big bring to the confidence level of measurement result and the defective of sensitivity influence, a kind of combined method of widely applicable, ultramicroelectrode that volume is little and the ultra-micro compound electrode that obtains of method and the preparation technology of this ultra-micro compound electrode thus are provided, be used for significantly to reduce solution resistance, greatly improve available speed and the detection sensitivity of sweeping, be reduced to the damage to research system minimum in the practical systems analysis.
For achieving the above object, technical scheme proposed by the invention is:
A kind of combined method of galvanochemistry ultramicroelectrode, it is characterized in that: it is that ultra micro working electrode and right/accurate contrast electrode combination are integrated, form two electrode systems, insulation course by nano thickness between described ultra micro working electrode and the right/accurate contrast electrode is isolated, make particle oxidation or reduction on an electrode of the diffusion layer generation coincidence back electrochemical reversible on two electrodes, and on another electrode, pass through to reduce or oxidation regeneration, and then return and diffuse on the original electrode, thereby the current signal of exporting on the electrode of surveying cell is exaggerated.
A kind of electrochemical ultra-micro compound electrode structure, it is characterized in that: it comprises ultra micro working electrode, right/accurate contrast electrode and glass capillary, described ultra micro working electrode one end seals and is fixed in the glass capillary, and its end points is connected with lead by conducting resinl; Even coating in described ultra micro working electrode other end surface or polymerization have the insulation course of a nano thickness, and this insulation course and described glass capillary outside surface evenly are coated with a metal level, and this metal level is drawn by another lead, constitutes right/accurate contrast electrode.
In the said structure, described ultra micro working electrode is carbon material basic electrode or metal ultramicroelectrode, preferably carbon fiber or carbon nanomaterial of carbon material basic electrode material wherein, and metal ultramicroelectrode material is preferably gold or platinum;
Described insulation course is made of insullac, epoxy resin or high molecular polymer;
Described right/accurate contrast electrode is made of gold, platinum, silver-colored precious metal material or Rare Metals Materials.
The present invention also provides the preparation technology of above-mentioned electrochemical ultra-micro compound electrode, it is characterized in that comprising following concrete steps:
Earlier that ultra micro working electrode one end is bonding by conducting resinl and lead, then this end is sealingly fastened in the kapillary, lead is exposed to extracapillary; Evenly apply in the unencapsulated surface of the ultra micro working electrode other end again or the insulation course of polymerization one nano thickness, evenly plate a metal level at this insulation course and glass capillary outside surface then, with lead draw make its formation right/accurate contrast electrode, to be coated with vertical cut-out of electrode front end of metal level and insulation course at last, the ultra micro working electrode cross section of exposing is as ultra-micro compound electrode.
In the said method, the coating processes of described insulation course is that the ultra micro working electrode is immersed in insullac or the epoxy resin, takes out oven dry after 1~5 minute, and the THICKNESS CONTROL of its insulation course is between 100-500nm;
Being polymerized to of described insulation course immersed the ultra micro working electrode in phenol and the 2-allyl benzene phenol solution, on the ultra micro working electrode, apply the voltage of 2V~5V, make above-mentioned two kinds of chemical substance polymerizations, form the high molecular polymerization insulation course at the ultra micro working electrode surface, the THICKNESS CONTROL of its insulation course is between 10-50nm;
Described metal level coating adopts the method for evaporation or sputter to plate one deck gold, platinum, silver metal or rare metal at insulation course and kapillary outer wall, and its metal layer thickness is controlled between the 50-80nm.
Further as its preparation technology, the present invention in the ultra micro working electrode the bonding lead and be sealed in kapillary before, the ultra micro working electrode that is made of the carbon material adopts acetone, ethanol, distilled water or its potpourri ultrasonic cleaning clean also dry, and the ultra micro working electrode that is made of gold or platinum metal material adopts nitric acid, chloroazotic acid to clean and drying.
Compared with prior art, the present invention has following technique effect:
(1) the present invention is by making up integrated two electrode systems with ultra micro working electrode and right/accurate contrast electrode, and the insulation course with nano thickness between ultra micro working electrode and the right/accurate contrast electrode is isolated, the ultra-micro compound electrode volume of Gou Chenging is little thus, working electrode and right/accurate contrast electrode can place system to be measured simultaneously, so can greatly reduce the disturbance of pair cell vital movement system, can be reduced to minimum to the damage that system is caused;
(2) the present invention is because the mutual coincidence of diffusion layer on ultra-micro compound electrode, and the particle of electrochemical reversible can produce the oxidation-reduction and regeneration circulation, can make that output current signal obtains amplifying on the electrode of surveying cell, thereby has greatly improved detection sensitivity;
(3) ultra-micro compound electrode of the present invention's formation has reduced solution resistance to a great extent, and employed feedback resistance and compensating resistance also can correspondingly reduce, thereby can not influence the bandwidth of instrument and circuit;
(4) ultra-micro compound electrode of the present invention can greatly improve the available speed of sweeping of practical systems analysis, can capture dynamic information of moment, helps the electron transfer and the Chemical Kinetics of deep study and analysis system;
(5) ultra-micro compound electrode long service life of the present invention is exposed fresh working electrode with vertical cut-out of electrode front end, can realize the renewal to electrode, and is simple to operate, good stability;
(6) ultra-micro compound electrode preparation technology of the present invention is simple, practical, processing ease, and manufacturing conditions is controlled easily, and is with low cost, all can make at general chemical laboratory, has application value preferably.
Ultra-micro compound electrode provided by the invention can significantly reduce solution resistance, greatly improve available speed and the detection sensitivity of sweeping in the practical systems analysis, be reduced to the damage to research system minimum, be a kind of high performance electrochemica biological sensor, the high time-space resolution detection of dynamic and the interior single vesica of pair cell that can be used for unicellular release carry out the real-time and dynamic analysis and research.
[description of drawings]
Fig. 1 is the structure end face and the side schematic view of electrochemical ultra-micro compound electrode of the present invention;
Fig. 2 is the 12mmol/L anthracene with 0.1mol/L tetraethylammonium tetrafluoroborate (NEt
4BF
4) cyclic voltammogram when sweeping speed for 1.34MV/s in the acetonitrile solution of supporting electrolyte;
Fig. 3 is that 10 μ mol/L DA sweep the differential pulse voltammetry figure of speed when the 20mV/s in the 0.1mol/L phosphate buffer solution on gold/platinum ultra-micro compound electrode;
Fig. 4 is the differential pulse voltammetry figures of 10 μ mol/L DA when sweeping speed for 20mV/s on ultra micro gold disc electrode in the 0.1mol/L phosphate buffer solution;
Fig. 5 sweeps speed for the 1.0mmol/L potassium ferricyanide respectively and is the cyclic voltammogram of 100mV/s on carbon fiber/platinum ultra-micro compound electrode and the fine card electrode of carbon in the 0.5mol/l Klorvess Liquid.
Among its Fig. 1:
1, ultra micro working electrode, 2, glass capillary, 3, conducting resinl, 4, lead, 5, insulation course, 6, metal level, 7, epoxy resin; M, end face, N, side.
[embodiment]
The invention provides a kind of combined method of widely applicable, ultra-micro compound electrode that volume is little and the ultra-micro compound electrode that obtains of method and the preparation technology of this ultra-micro compound electrode thus.
At first, the invention provides a kind of combined method of electrochemical ultra-micro compound electrode, it is that ultra micro working electrode and right/accurate contrast electrode combination are integrated, form two electrode systems, insulation course with nano thickness between ultra micro working electrode and the right/accurate contrast electrode is isolated, like this, can make the diffusion layer on two electrodes overlap, the particle of electrochemical reversible can obtain oxidation or reduction on an electrode, and on another electrode, obtain regeneration, and then return and diffuse on the original electrode by reduction or oxidation.Because ultra micro working electrode and right/accurate contrast electrode are integrated, after separating with insulation course between ultra micro working electrode and the right/accurate contrast electrode, this moment, two electrodes were in short-circuit condition.According to the mass transfer diffusion theory of ultra micro disk electrode, the expression formula of mass transfer rate Ms is as follows:
D is the coefficient of diffusion of particle in the formula, and r is the radius of disk electrode.In time t, the displacement of particle in the diffusion field, promptly thickness of diffusion layer is M
sT.Suppose r=3 μ M, particle is typical diffusion coefficient D=5 * 10 in aqueous solution
-6Cm
2/ s sweeps speed when the kV/s, and finishing the single pass required time is the ms level, so thickness of diffusion layer can reach hundreds of nm, along with the raising of sweeping speed, the corresponding attenuation of thickness of diffusion layer.Obviously, thickness by reasonable control insulation course, diffusion layer on ultra micro working electrode and the right/accurate contrast electrode will overlap, this moment, the particle of electrochemical reversible obtained oxidation or reduction on an electrode, and on another electrode, obtain regeneration by reduction or oxidation, and then return and diffuse on the original electrode, therefore producing the current signal that redox cycle makes output obtains amplifying, and amplification multiple depends on the thickness of described insulation course and the dynamics and the electrochemical properties of particle, in general, insulation course is thinner, and the reaction kinetics of particle is faster, and amplification multiple is then bigger.Fen Xiyanjiu the available speed of sweeping also is improved simultaneously.
The above-mentioned theory basis has been arranged, understood the structure of ultra-micro compound electrode among the present invention again according to Fig. 1.As shown in Figure 1, a kind of electrochemical ultra-micro compound electrode that the present invention is designed according to said method, comprise ultra micro working electrode 1 and glass capillary 2, described ultra micro working electrode 1 part places in the glass capillary 2, it is inserted glass capillary 7 interior ultra micro working electrode 1 end points and is connected with a lead 4.1 by conducting resinl 3, these lead 4.1 usefulness epoxy resin 7 are sealingly fastened in the glass capillary 2, and expose outside the glass capillary 2 its termination; At described ultra micro working electrode 1 other end outside surface, evenly coating or polymerization have the insulation course 5 of one deck nano thickness, this insulation course 5 and described glass capillary 7 outside surfaces evenly are coated with layer of metal layer 6, this metal level 6 is drawn by another lead 4.2, become described right/accurate contrast electrode, form the integrated combined electrode structure of ultra micro working electrode and right/accurate contrast electrode.
In the combinations thereof electrode structure, described ultra micro working electrode 1 can be carbon material basic electrode or metal electrode, wherein carbon material basic electrode can be made of carbon fibre material or carbon nanomaterial, metal electrode can be metal materials such as gold, platinum and makes, the advantage that adopts above-mentioned material is the electrode good biocompatibility of making, some biomolecule there is the electrochemical catalysis effect, and buys conveniently, make simple.
Described insulation course 5 is made of insullac, epoxy resin or high molecular polymer, wherein insullac can be anodic electrophoresis paint, cathode electrodip painting or vehicle paint base etc., high molecular polymer can be the galvanochemistry inert polymers such as multipolymer of poly-o-phenylenediamine, polyvinyl pyridine, poly-(L-lysine), phenol and 2-chavicol, the advantage that adopts above-mentioned material is that insulation course 5 insulation effect that constitute thus are good, dielectric film is evenly fine and close, good stability.
Described metal level 6 is by precious metal material or Rare Metals Materials (as rhodium, iridium etc.) formations such as gold, platinum, silver, the advantage that adopts above-mentioned material is that the right/accurate contrast electrode conductive capability that constitutes thus is strong, electrochemical properties is stable, and the surface is cleaned easily, is difficult for contaminated.
The ultra-micro compound electrode structure preparation technology designed according to the combinations thereof method is:
Earlier that ultra micro working electrode 1 one ends are bonding by conducting resinl 3 and lead 4.1, then this electrode part is sealingly fastened in the glass capillary 2, lead 4.1 terminations are exposed to outside the glass capillary 2; Even coating of a unencapsulated end surfaces outside ultra micro working electrode 1 exposes glass capillary 2 or polymerization have the insulation course 5 of a nano thickness again, evenly plate a metal level 6 at this insulation course 5 and glass capillary 2 outside surfaces then, with lead 4.2 draw make its formation right/accurate contrast electrode, to be coated with vertical cut-out of electrode front end of metal level 6 and insulation course 5 at last, the ultra micro working electrode cross section of exposing is as ultra-micro compound electrode.
In the above-mentioned manufacturing process, the coating processes of described insulation course 5 is: ultra micro working electrode 1 is immersed in insullac or the epoxy resin, took out after 1~5 minute, 60 ℃~80 ℃ oven dry down, the THICKNESS CONTROL of its insulation course 5 is between 100-500nm then.Experiment showed, that the insulation course of selecting above-mentioned thickness can sweep that the diffusion layer of electroactive particle on working electrode and right/accurate contrast electrode overlaps under the speed medium, the electrochemical response signal is able to regenerative amplification, thereby improves the sensitivity of detection.
The polymerization technique of described insulation course 5 is: ultra micro working electrode 1 is immersed in phenol and the 2-allyl benzene phenol solution, on ultra micro working electrode 1, apply the voltage of 2V~5V then, make above-mentioned two kinds of chemical substances produce polymerization, can form the high molecular polymerization insulation course on ultra micro working electrode 1 surface, the THICKNESS CONTROL of its insulation course 5 is between 10-50nm.Experiment showed, and select the insulation course of above-mentioned thickness can greatly reduce solution resistance, improve the available speed of sweeping of practical systems analysis greatly, be convenient to the electron transfer and the Chemical Kinetics of research system.
The coating processes of described metal level 6 is: evaporation or sputtering method (for prior art processes) plate noble metal or rare metals such as one deck gold, platinum, silver at insulation course 5 and glass capillary 2 outer walls, and its metal level 6 THICKNESS CONTROL are between 50-80nm.Experiment showed, the metal level good conductivity of selecting above-mentioned thickness, stable, difficult drop-off.
For removing electrode surface impurity, further improve detection sensitivity and detect quality, described ultra micro working electrode 1 is at bonding lead 4.1 and before being sealed in glass capillary 2, adopt cleaning that it is cleaned, the ultra micro working electrode 1 that wherein is made of material with carbon element adopts clean and do dried with acetone, ethanol, distilled water or its potpourri ultrasonic cleaning, and 1 of the ultra micro working electrode that is made of gold or platinum metal material adopts nitric acid, chloroazotic acid cleaning and does dried.
Below specific embodiment by preparation technology and application and accompanying drawing are resolved characteristics of the present invention and advantage again.
Embodiment 1: carbon fiber/gold (CF/Au) ultra-micro compound electrode
Select for use carbon fiber electrode and gold to be used as the combination of two electrodes in the present embodiment, clean with ethanol, distilled water ultrasonic cleaning; Conducting resinl adopts silver conductive adhesive; Insulation course adopts polymerization methods to form.Its concrete manufacture craft is: earlier carbon fiber electrode is placed acetone to reflux 8 hours, use ethanol, distilled water ultrasonic cleaning again, intercepting 3cm length behind the bone dry, be adhered to the copper wire end of 0.1mm then with silver conductive adhesive, place 1.0mm glass capillary, on the glass capillary drawing device carbon fiber electrode is sealed in this glass capillary, the copper conductor that the glass capillary other end exposes is fixed with epoxy sealing; Again carbon fiber electrode is immersed in phenol and the 2-allyl benzene phenol solution, on carbon fiber electrode, keep the about 5~7min of constant potential 4V, make phenol and 2-chavicol in carbon fiber surface generation polymerization, behind 140 ℃ of high-temperature bakings, form the insulation course that thickness is about 10nm, evaporation plates the thick gold of the about 70nm of one deck on insulation course, with copper conductor draw the back as right/accurate reference to electrode, at last, with being coated with vertical cut-out of the fine electrode front end of carbon of gold layer and insulation course, promptly obtain carbon fiber/gold (CF/Au) ultra-micro compound electrode.With above-mentioned identical disposal route, after the fine electrode surface of carbon forms insulation course, directly the electrode front end is cut off, Gold plated Layer does not promptly obtain the fine card electrode of carbon.
The fine card electrode of above-mentioned carbon fiber/gold (CF/Au) ultra-micro compound electrode that makes and carbon is used to detect anthracene to be compared: insert the NEt with 0.1mol/L respectively
4BF
4In the acetonitrile solution for the 12mmol/L anthracene of supporting electrolyte, survey the cyclic voltammetric characteristic under the speed, obtain accompanying drawing 2 sweeping of 1.34MV/s.Volt-ampere curve a uses with tradition two electrode systems of the fine card electrode of carbon as working electrode among the figure, because supporting electrolyte concentration is low, and R
sBigger, under the prerequisite of holding circuit bandwidth, can not realize 100% compensation, only can compensate approximately 40%, can't differentiate the faraday peak; Curve b uses ultra-micro compound electrode, because R
sObviously reduce, the ohmmic drop reduces, and can be clear that the faraday peak, if but uncompensation, the ohmmic drop still has remnants, so peak separation Δ E
pBigger than theoretical value.But can pass through electronics positive feedback technique full remuneration ohmmic drop this moment, and shown in volt-ampere curve c, this moment, empirical curve c and simulation curve d were identical substantially.
Embodiment 2: gold/platinum (Au/Pt) ultra-micro compound electrode
The preparation technology of gold/platinum (Au/Pt) ultra-micro compound electrode is similar to Example 1, after confirming the good various materials and method that use, at first with the spun gold of diameter 5nm at nitric acid, clean in the distilled water, dry back is bonding with conducting resinl and copper conductor, place kapillary to draw sealing, at spun gold surface-coated insullac, obtain the insulation course that thickness is 120nm after the oven dry, the thick platinum of sputter last layer 50nm outside insulation course then, draw as right/accurate reference electrode with copper conductor, at last, will be coated with vertical cut-out of gold electrode front end of platinum layer and insulation course, promptly obtain gold/platinum (Au/Pt) ultra-micro compound electrode.With above-mentioned identical disposal route, after gold electrode surfaces forms insulation course, directly the electrode front end is cut off, no longer the sputter platinum layer promptly obtains ultra micro gold disc electrode.
Above-mentioned gold/the platinum that makes (Au/Pt) ultra-micro compound electrode and ultra micro gold disc electrode is used for detecting neurotransmitter dopamine to be compared: the 0.1mol/L phosphate buffer solution that inserts 10 μ mol/L DA, error of measurement divides the pulse volt-ampere characteristic under 20mV/s, obtains accompanying drawing 3; Ultra micro gold disc electrode is inserted in the above-mentioned identical solution, and error of measurement divides the pulse volt-ampere characteristic under 20mV/s, obtains accompanying drawing 4.As seen Fig. 3 curve is compared with Fig. 4 curve, and the electrochemical oxidation differential pulse peak current of DA on the Au/Pt ultra-micro compound electrode improved nearly 10000 times than the differential pulse peak current on the ultra micro gold disc electrode.
Embodiment 3: carbon fiber/platinum (CF/Pt) ultra-micro compound electrode;
The cleaning treatment of carbon fiber is identical with embodiment 1, evenly be coated with last layer epoxy resin at clean carbon fiber surface, about 450nm is thick behind the bone dry, at the thick platinum of epoxy surface sputtering last layer 50nm, draw as right/accurate reference electrode with copper conductor, at last, with being coated with vertical cut-out of the fine electrode front end of carbon of platinum layer and epoxy insulation layer, promptly obtain carbon fiber/platinum (CF/Pt) ultra-micro compound electrode.With above-mentioned identical disposal route, after the fine electrode surface of carbon forms insulation course, directly the electrode front end is cut off, no longer the sputter platinum layer promptly obtains the fine card electrode of carbon.
The fine card electrode of the above-mentioned carbon fiber/platinum that makes (CF/Pt) ultra-micro compound electrode and carbon is used for detecting the potassium ferricyanide to be compared: the 0.5mol/l Klorvess Liquid that the CF/Pt ultra-micro compound electrode is inserted the 1.0mmol/L potassium ferricyanide, under 100mV/s, survey the cyclic voltammetric characteristic, obtain the curve a in the accompanying drawing 5; The fine card electrode of carbon is inserted in the above-mentioned identical solution, under 100mV/s, survey the cyclic voltammetric characteristic, obtain the curve b in the accompanying drawing 5.As seen curve a is compared with curve b, and the electrochemical response of the potassium ferricyanide on the CF/Pt ultra-micro compound electrode improved nearly 4 times than the response current on the fine card electrode of carbon.
Can see after embodiment by above three preparation technologies and the concrete comparative analysis, the ultra micro work in combination electrode that foundation combined method of the present invention makes, it is big to have overcome the solution resistance that the conventional electrodes system exists in detection, it is low to sweep speed, to problem such as the interference of research system is big, can significantly reduce solution resistance, the oxidation-reduction and regeneration circulation can take place on this compound electrode the particle of electrochemical reversible makes the current signal of output obtain amplifying, therefore can greatly improve the available speed and the detection sensitivity of sweeping of practical systems analysis, damage to research system is reduced to minimum, this ultra-micro compound electrode is easy to make, long and renewal easily of life-span, be a kind of high performance electrochemica biological sensor, the high time-space resolution detection of dynamic and the interior single vesica of pair cell that can be used for unicellular release carry out the real-time and dynamic analysis and research.