WO2019003328A1

WO2019003328A1 - Measuring pipette tip, and measurement device and measurement method using said measuring pipette tip

Info

Publication number: WO2019003328A1
Application number: PCT/JP2017/023676
Authority: WO
Inventors: 佳則山口; 暁鳴竇
Original assignee: 佳則山口; 暁鳴竇
Priority date: 2017-06-28
Filing date: 2017-06-28
Publication date: 2019-01-03
Also published as: JP6668477B2; JPWO2019003328A1

Abstract

This measuring pipette tip has: a suction port for suctioning a sample solution at the distal end of the measuring pipette tip; and an inner space for retaining a prescribed amount of the sample solution suctioned via the suction port. The measuring pipette tip is attached to the distal end of a pipette. The measuring pipette tip has: a measuring electrode; and a tip-side terminal. The measuring electrode is provided in a position so as to be in contact with the sample solution suctioned via the suction port and retained in the inner space, and is used for electrochemically measuring the sample solution. The tip-end terminal is for electrically connecting an electrical circuit provided on the outside of the measuring pipette tip to the measuring electrode.

Description

Pipette tip for measurement, measuring apparatus and measuring method using the pipette tip for measurement

The present invention relates to a measurement pipette tip for performing an electrochemical measurement of a liquid, a measurement device and a measurement method using the measurement pipette tip.

Since heavy metals such as cadmium, cobalt, mercury, copper and zinc are harmful to the human body, it is very important to understand how much heavy metal is contained in water and soil. Therefore, various methods have been proposed and implemented as methods of measuring heavy metals (see, for example, Patent Documents 1 and 2). In addition, the problem of pesticide residue caused by spraying pesticides to food such as grains, vegetables and fruits is serious, and in 2013, 23 children died from monocrotophos remaining in vegetables in India Serious incidents are happening.

Also, for example, in the case of quantitatively analyzing chemical substances such as heavy metals and dioxins which are contained only in trace amounts in soil, conventionally, soil is collected and the soil is shaken with water and eluted in water Or, the soil is heated and decomposed in an acid solution to form a solution, which is used as a sample for analysis, and the optical characteristics of the sample for analysis are measured using an ICP emission spectrophotometer or an atomic absorption spectrometer. (See Non-Patent Document 1). Furthermore, for the inspection of pesticide residues, it is common to measure their type and concentration using a high-speed chromatography mass spectrometer or capillary electrophoresis, the measuring device is large and expensive, and it is special to use It is nearly impossible to test pesticides before cooking for food, especially foods that require pesticides, which requires considerable training and considerable expertise.

Unexamined-Japanese-Patent No. 11-174054 JP, 2009-034041, A

The above method using an ICP emission spectrometer or atomic absorption spectrometer can perform precise quantitative analysis of a trace amount of heavy metal or chemical substance, while an apparatus such as an ICP emission spectrometer or atomic absorption spectrometer is It is extremely expensive, and its handling such as measurement operations requires skill. Furthermore, devices such as an ICP emission spectrochemical analysis device can be used only in a room such as a laboratory, and it is difficult to perform so-called field measurement in which analysis is performed on site such as a soil collection site. The same applies to the inspection of residual pesticides, and it is almost impossible to bring an expensive and large high-performance liquid chromatography mass spectrometer on site, that is, a cooking site, and conduct inspection before cooking.

In addition, wavelength dispersive X-ray fluorescence analyzers and energy dispersive X-ray fluorescence analyzers are also known as apparatuses capable of analyzing metal substances such as heavy metals. However, there is a problem that sufficient X-ray intensity can not be obtained even when trying to quantitatively analyze a specific component which is contained in a very small amount in a sample using a wavelength dispersive fluorescent X-ray analyzer, and the detection sensitivity is insufficient. Further, the wavelength dispersive fluorescent X-ray analyzer is as expensive as an ICP emission spectrometer, an atomic absorption spectrometer, and the like. Energy dispersive X-ray fluorescence analyzers are smaller and cheaper than wavelength dispersive X-ray fluorescence analyzers, and are relatively easy to handle, but they can be measured if they contain only a small amount of specific components. There is a problem of lack of sensitivity. Furthermore, for analysis of residual pesticides, decomposition by ionization process when measuring with a mass spectrometer, ionization of target pesticides depending on the presence or absence of ionization due to differences in chemical properties of target substances, or ionization of all substances There is a problem that it can not do. In addition, in high performance liquid chromatography analysis, it is almost impossible to measure the pesticide residue on vegetables before cooking in-situ because of the choice of mobile phase and stationary phase, and the use of highly toxic solution to mobile phase. It is impossible.

In recent years, heavy metal measurement using electrochemical measurement has also been performed, and there is also a small electrochemical measurement apparatus using a carbon thin film as an electrode. As a small-sized electrochemical measurement apparatus, there is one in which a fine measurement electrode made of carbon is formed on a flat substrate by sputtering. When measurement is performed using such an electrochemical measurement device, the sample solution must be aspirated by a pipette, dropped onto the portion of the measurement electrode of the electrochemical measurement device, and the sample solution should be in contact with the measurement electrode. You must. However, it is not easy to ensure that a minute amount of sample solution is in contact with the fine measurement electrode.

Conventionally, there is a method of measuring metal ions such as ammonia, cyanide, chlorine and the like using a glass electrode called an ion electrode or a PH electrode. This electrode is a complex, more fragile, and expensive in which a standard electrode, a working electrode, a standard solution and a counter electrode are included in a glass tube. Because of the high cost and the standard solution enclosed inside are dangerous substances and highly toxic substances, they can not be used on site for the purpose of simple measurement. Moreover, the enzyme electrode which fix | immobilized the enzyme on the electrode surface is raised as an example using a disposable electrode. An enzyme immobilized on the surface of an electrode, such as glucose oxidase (GOD), quantifies the concentration of glucose using the reducing power when GOD and glucose react. However, even when the electrode is used, sampling is often difficult, and there is also a possibility of contamination due to spattering of blood and the like.

Therefore, it is an object of the present invention to ensure that even if the sample solution is a trace amount of sample solution, the sample solution is brought into contact with the measurement electrode so that the electrochemical measurement of the sample can be easily performed.

The measurement pipette tip according to the present invention has a suction port for sucking the sample solution at the tip and an internal space for storing a predetermined amount of sample solution sucked from the suction port, and the tip of the pipette It is attached to The measurement pipette tip has a measurement electrode and a tip side terminal. The measurement electrode is provided at a position in contact with the sample solution sucked in from the suction port and stored in the internal space, and is for performing electrochemical measurement of the sample solution. The tip side terminal is for electrically connecting an electric circuit provided outside the measurement pipette tip to the measurement electrode.

Here, the electrochemical measurement in the present invention includes the measurement of the electrical conductivity of the sample solution, the measurement of the characteristic of the chemical change on the electrode surface, for example, the electrochemical reaction of the chemical reaction on the enzyme-modified electrode surface. It includes measurement, measurement of electrochemical reactions on the electrode surface in a mixed system of 2 and 3 solutions, and measurement of electrochemical reactions in which absorption and light emission are electronically converted on the electrode surface.

The measuring apparatus according to the present invention has a tip mounting portion for mounting the above-mentioned measurement pipette tip, and an internal space communicating with the tip mounting portion, and the piston slides in the internal space. A syringe unit configured to aspirate a predetermined amount of sample solution from the tip of the measurement pipette tip attached to the tip attachment unit; a tip side terminal of the measurement pipette tip attached to the tip attachment unit; Electrically connected to the device side terminal for electrical connection and the measurement electrode of the measurement pipette tip through the device side terminal, and aspirated from the tip of the measurement pipette tip through the measurement electrode And a measurement circuit for performing an electrochemical measurement of the sample solution.

That is, the measurement apparatus according to the present invention mounts the measurement pipette tip on the tip mounting portion, electrically connects the device-side terminal to the tip-side terminal of the measurement pipette tip, and operates the piston of the syringe unit The apparatus is configured such that electrochemical measurement of the sample solution can be performed via the measurement electrode of the measurement pipette tip by simply aspirating a predetermined amount of sample solution from the suction port of the tip of the measurement pipette. It is.

In a preferred embodiment of the measuring device according to the present invention, the tip side terminal of the measuring pipette tip is provided in an internal space of the measuring pipette tip, and the device side terminal is mounted on the tip mounting portion. It is provided in the said tip mounting part so that the said tip side terminal of the pipette tip for measurement may be contacted. Thus, the measurement circuit can be electrically connected to the measurement electrode provided on the measurement pipette tip simply by attaching the measurement pipette tip to the tip mounting portion.

In the above case, the tip mounting portion has a shape fitted into the opening provided at the proximal end of the measurement pipette tip with a fixed positional relationship, and the tip mounting portion is in the opening of the measurement pipette tip It is preferable that the device-side terminal be positioned relative to the chip-side terminal when fitted in a fixed positional relationship. Then, contact failure due to misalignment between the device side terminal and the chip side terminal is less likely to occur, and connection of the measurement circuit to the measurement electrode can be made more reliably.

In the measuring apparatus of the present invention, it is preferable that a display unit for displaying the measurement result by the measurement circuit is provided on the outer surface. Then, the user can immediately confirm the measurement result of the sample solution aspirated from the tip of the measurement pipette.

The measurement method according to the present invention comprises the steps of: attaching the measurement pipette tip of the present invention to the tip of a pipette; aspirating a sample solution from the tip of the measurement pipette tip; and providing the inside of the measurement pipette tip The method comprises the steps of: bringing a sample solution into contact with a measurement electrode; and performing an electrochemical measurement of the sample solution drawn from the tip of the measurement pipette tip through the measurement electrode.

The pipette is preferably the above measuring device. Then, the measurement of the sample solution aspirated from the tip of the measurement pipette tip can be performed immediately and conveniently.

In the measurement pipette tip of the present invention, a measurement electrode is provided at a position in contact with the sample solution sucked from the suction port at the tip and stored in the internal space, and for connecting an external electric circuit to the measurement electrode. Since the tip side terminal is provided, the measurement pipette tip is attached to the tip of the pipette, and while the electric circuit for measurement is connected to the tip side terminal, a predetermined amount of sample solution is aspirated from the suction port of the tip. Thus, the sample solution can be reliably brought into contact with the measurement terminal, and the electrochemical measurement of the sample solution can be easily performed. In addition, since it is possible to attach to a pipette and sample by aspiration, measurement of biochemical samples such as saliva, urine and blood in the oral cavity should be performed in a situation where contamination is prevented and the experimenter is unlikely to be infected. It will be possible.

In the measuring apparatus of the present invention, the above-mentioned pipette tip for measurement is attached to the tip attaching portion, the device side terminal is electrically connected to the tip side terminal of the pipette tip for measurement, and measurement is performed by operating the piston of the syringe portion The sample solution is constructed so that electrochemical measurement can be performed via the measurement electrode of the measurement pipette tip simply by suctioning a predetermined amount of sample solution from the suction port of the tip of the pipette. The electrochemical measurement of the solution can be conveniently performed.

Furthermore, since the measuring device of the present invention has a function as a syringe, it is possible to hold the sample solution in an accurate volume, and an analysis method in which the sample amount is required to be accurate, for example, analysis by absorbance analysis or fluorescence analysis, It is possible to guarantee the accuracy of sampling. In addition, since it is possible to sample the sample from the tip of the measurement pipette tip by aspiration, measurement of biochemical samples such as saliva, urine and blood in the oral cavity is prevented from contamination and it is difficult for the experimenter to get infected It can be done in situations.

In the measurement method of the present invention, the above-mentioned pipette tip for measurement is attached to the tip of the pipette, a predetermined amount of sample solution is aspirated from the tip of the measurement pipette tip, and the sample solution is brought into contact with the measurement electrode Since the electrochemical measurement of the sample solution drawn from the tip of the measurement pipette tip through the electrode is performed, the sample solution can be reliably brought into contact with the measurement electrode even if the amount of the sample solution is very small. Electrochemical measurement can be easily performed.

It is a perspective view which shows one Example of the pipette tip for measurement. (A) is sectional drawing which shows the internal structure of the pipette tip for measurement of the Example, (B) is a top view of the electrode substrate of the pipette tip. It is a front view which shows one Example of a measuring apparatus. It is a figure which shows the state which mounted the pipette tip for measurement to the measuring apparatus of the Example. It is a block diagram which shows roughly the circuit structure of the measuring apparatus of the Example. It is a flowchart which shows the measuring method using the measuring apparatus of the Example in order of a process.

Hereinafter, embodiments of a measuring pipette tip and a measuring apparatus and measuring method using the measuring pipette tip will be described with reference to the drawings.

First, one embodiment of the measurement pipette tip will be described with reference to FIGS. 1 and 2. FIG.

As shown in FIG. 1, the measurement pipette tip 2 is used by being attached to the tip of a later-described pipette-type measurement device 24 (see FIG. 4). The measurement pipette tip 2 has a shape that becomes thinner as it goes from the proximal side to the distal side. The distal end is provided with a suction port 4 for sucking the liquid, and the proximal end is provided with an opening 6 into which the distal end portion of the measuring device 24 is inserted. The suction port 4 at the tip is designed so that the suctioned solution is held without dripping during measurement.

As shown in FIG. 2A, a space 8 for storing a predetermined amount of sample solution sucked from the suction port 4 at the tip is provided inside the measurement pipette tip 2, The opening 6 at the proximal end communicates with the suction port 4 at the distal end via the space 8. A flat electrode substrate 10 is fixed in the space 8. The inner diameter of the suction port 4 at the tip prevents the sample solution in the space 8 from being dropped from the suction port 4 when the suction port 4 is directed vertically downward after sucking a predetermined amount of sample solution from the suction port 4 Size (for example, 0.5 mm or less).

As shown in FIG. 2B, three

measurement electrodes

12, 14, 16 are provided on one end side (right side in the figure) of the electrode substrate 10. As shown in FIG. The

measurement electrodes

12, 14 and 16 are for performing electrochemical measurement, and any one of them serves as a working electrode, a reference electrode, and a counter electrode. The measuring

electrodes

12, 14 and 16 are drawn to the other end side of the electrode substrate 10 to form

connection terminals

18, 20 and 22 (chip side terminals).

The electrode substrate 10 has one end provided with the

measurement electrodes

12, 14 and 16 at the tip end side of the measurement pipette tip 2 and the other end provided with the

terminals

18, 20 and 22 at the base of the measurement pipette tip 2. It is arranged to face the end side. In the electrode substrate 10, when a predetermined amount (for example, 10 μL) of the sample solution is drawn into the space 8 in the measurement pipette tip 2, the

measurement electrodes

12, 14, 16 contact the sample solution, and the

terminals

18, 20 , 22 are provided at positions not in contact with the sample solution.

The

measurement electrodes

12, 14, 16 and the

terminals

18, 20, 22 of the electrode substrate 10 are made of, for example, a carbon thin film formed by sputtering or print printing. Plating may be applied to the surface of the carbon thin film according to the object to be measured. For example, when the object to be measured is a heavy metal such as arsenic or mercury, the surface of the carbon thin film can be plated with gold or the like, whereby the measurement sensitivity can be improved.

In this embodiment, the three

measurement electrodes

12, 14, 16 are provided on the electrode substrate 10. However, the number of electrodes may be two or four or more. If at least two measuring electrodes are provided, it is possible to perform the conductivity measurement of the sample solution.

Next, an embodiment of a measuring apparatus 24 using the above-described measuring pipette tip 2 will be described with reference to FIGS. 3 and 4.

The measuring device 24 has a function as a pipette for aspirating and discharging a liquid. A syringe unit 32 for suctioning and discharging a liquid and a measurement circuit board 42 for performing an electrochemical measurement are accommodated in the housing of the measuring device 24. The tip mounting portion 28 is provided at the distal end portion, and the tip mounting portion 28 is inserted into the opening 6 (see FIG. 1) provided at the proximal end of the measurement pipette tip 2 to measure the distal end portion. The pipette tip 2 is to be attached. An opening 30 communicating with the syringe unit 32 is provided on the tip end surface of the tip mounting unit 28.

A piston 34 is provided slidably inside the syringe unit 32 in one axial direction. By sliding the piston 34 in the syringe unit 32 in a state where the measurement pipette tip 2 is attached to the tip attachment unit 28, suction and discharge of liquid can be performed via the measurement pipette tip 2. A drive shaft 36 for driving the piston 34 protrudes from the base end surface of the housing 26, and a disc-like pressing portion 38 is provided at an end of the drive shaft 36.

Although illustration is omitted, the drive shaft 36 is biased to the base end side (upper side in the figure) by an elastic body such as a coil spring, and when the user presses the pressing portion 38 to the distal side (lower side in the figure) The drive shaft 36 is automatically returned to the proximal side by the elastic force of the elastic body.

A terminal portion 40 is provided at the tip of the chip mounting portion 28. As shown in FIG. 4, the terminal portion 40 contacts the

terminals

18, 20, 22 (see FIG. 2) of the electrode substrate 10 when the measurement pipette tip 2 is mounted on the tip mounting portion 28. It is provided to do. The terminal portion 40 is provided with device-side terminals corresponding to the

terminals

18, 20, 22 of the electrode substrate 10 in the measurement pipette tip 2, respectively. Each device-side terminal of the terminal unit 40 is electrically connected to the measurement circuit board 42.

Although not shown in the figure, the tip mounting portion 28 has a shape to be fitted into the opening 6 of the measuring pipette tip 2 with a fixed positional relationship, and the tip mounting portion 28 is fitted into the opening 6 of the measuring pipette tip 2 At this time, each device-side terminal of the terminal portion 40 is positioned with respect to the

terminals

18, 20, 22 of the electrode substrate 10. Thus, when the measurement pipette tip 2 is attached to the tip attachment portion 28, the measurement circuit board 42 provided inside the measurement device 24 becomes the measurement electrode 12 of the electrode substrate 10 of the measurement pipette tip 2, The electrochemical measurement of the sample solution S electrically connected to 14 and 16 and sucked from the suction port 4 can be performed via the

measurement electrodes

12, 14 and 16.

The amount of suction from the suction port 4 of the measurement pipette tip 2 may be always constant. For example, a predetermined amount (for example, 10 μL) of the sample solution is automatically aspirated only by releasing the pressing portion 38 all the way down and then releasing the hand. As a result, when the sample solution is aspirated from the suction port 4 of the measurement pipette tip 2, the sample solution reliably contacts the

measurement electrodes

12, 14, 16 of the electrode substrate 10.

The terminal portion 40 has any shape as long as each device-side terminal is in contact with each terminal 18, 20, 22 of the electrode substrate 10 when the measurement pipette tip 2 is attached to the tip attachment portion 28. It may be For example, each device-side terminal of the terminal unit 40 has an annular shape, and even if the corresponding terminals are in contact with each other regardless of the mounting direction of the measurement pipette tip 2 to the tip mounting unit 28 Good.

An operation unit 44 and a display unit 46 are provided on the outer surface of the housing 26 (a base end surface in this embodiment). The operation unit 44 is an operation button for the user to perform operations such as power on / off, start of measurement, and change of information displayed on the display unit 46. The display unit 46 is realized by, for example, a small liquid crystal display. The display unit 46 may be configured by a touch panel, and the display unit 46 may have the function of the operation unit 44. The operation unit 44 and the display unit 46 are both electrically connected to the measurement circuit board 42.

Although not shown in FIGS. 3 and 4, the measuring device 24 includes a power supply unit 48 (see FIG. 5). The power supply unit 48 can be realized by, for example, a dry battery or a charge battery. The power supply unit 48 supplies necessary power to the measurement circuit board 42 and the display unit 46.

An example of the circuit configuration of the measuring device 24 will be described using the block diagram of FIG.

The measurement circuit board 42 includes an arithmetic control unit 50, a voltage application unit 52, and a current detection unit 54. The arithmetic control unit 50 performs predetermined arithmetic processing using the measurement values obtained by the electrochemical measurement, and is necessary for the voltage application unit 52 based on a command from the user input through the operation unit 44. It is a function of transmitting a signal or displaying information such as a measurement result on the display unit 46. The arithmetic control unit 50 is, for example, a function realized by the microcomputer executing a predetermined program.

When the voltage application unit 52 receives the measurement start signal from the operation control unit 50, the two measurement electrodes (working electrode and reference electrode) of the measurement pipette tip 40 via the device side terminal of the terminal unit 40 It is configured to apply a voltage of a predetermined magnitude between them.

The current detection unit 54 is configured to detect the magnitude of the current flowing between the two measurement electrodes (the working electrode and the counter electrode) of the measurement pipette tip 40 via the device side terminal of the terminal unit 40. The current detection unit 54 takes in a signal relating to the magnitude of the detected current to the calculation control unit 50.

The arithmetic control unit 50 calculates the concentration of a specific component or the like in the sample solution using, for example, a calibration curve prepared in advance, based on the signal received from the current detection unit 54, and displays the measurement result on the display unit 46. Is configured as.

The detection device 24 also includes an external output unit 56 so that information can be output to an external device such as a personal computer by wired communication means such as a USB (universal serial bus) terminal or wireless communication means. It is also good. In that case, the arithmetic control unit 50 is configured to output measurement data and the like to an external device via the external output unit 56.

An example of the measurement method using the measurement pipette tip 2 and the measurement apparatus 24 described above will be described using the flowchart of FIG. 6 together with FIG.

First, the measurement pipette tip 2 is attached to the tip of the detection device 24 (step S1). The tip of the measurement pipette tip 2 is immersed in the sample solution, and a predetermined amount of sample solution S is aspirated (step S2). Thereby, the

measurement electrodes

12, 14 and 16 are immersed in the sample solution S in the measurement pipette tip 2 (see FIG. 4).

In this state, for example, when the user presses the measurement start button (the operation unit 44), the arithmetic control unit 50 issues a signal to start the measurement to the voltage application unit 52, and the voltage application unit 52 has two measurement electrodes (function A voltage of a predetermined magnitude is applied between the electrode and the reference electrode (step S3). After a predetermined time (for example, 30 seconds) has elapsed since the voltage application, the current detection unit 54 measures the current value flowing between the two measurement electrodes (working electrode and counter electrode) (step S4).

The arithmetic control unit 50 quantifies the concentration of the specific component in the sample solution based on the current value measured by the current detection unit 54 (step S5), and displays the measurement result on the display unit 46 (step S6).

As described above, the measuring device 24 of the embodiment has the measuring pipette tip 2 attached to the tip thereof, and only suctions a predetermined amount of sample solution from the suction port 4 to obtain the measuring

electrodes

12, 14, 16. Since the sample solution can be reliably brought into contact with the sample solution to perform electrochemical measurement of the sample solution, simple and rapid electrochemical measurement can be performed.

2 pipette tip for measurement 4 suction port 6 opening of pipette tip for measurement 8 space in pipette tip for measurement 10

electrode substrate

12, 14, 16

measurement electrode

18, 20, 22 terminal (tip side terminal)
24 Measurement device 26 Case 28 Tip mounting portion 30 Opening of measurement device 32 Syringe portion 34 Piston 36 Drive shaft 38 Pressing portion 40 Terminal portion (Device side terminal)
42 Measurement circuit board (measurement circuit)
44 operation unit 46 display unit 48 power supply unit 50 arithmetic control unit 52 voltage application unit 54 current detection unit 56 external output unit

Claims

A measuring pipette tip attached to a tip of a pipette, having a suction port for sucking a sample solution at a tip and an internal space for storing a predetermined amount of sample solution sucked from the suction port. ,
A measurement electrode provided at a position to be in contact with the sample solution sucked from the suction port and stored in the internal space, and for performing electrochemical measurement of the sample solution;
And a tip side terminal for electrically connecting an electric circuit provided outside the measurement pipette tip to the measurement electrode.
A tip mounting unit for mounting the measurement pipette tip according to claim 1;
It has an internal space in communication with the tip mounting portion, and when the piston slides in the internal space, the sample solution is drawn from the tip of the measurement pipette tip mounted on the tip mounting portion. The syringe unit,
An apparatus-side terminal for electrically connecting to a tip-side terminal of the measurement pipette tip mounted to the chip mounting portion;
A measurement circuit electrically connected to the measurement electrode of the measurement pipette tip via the device-side terminal, and performing electrochemical measurement of a sample solution drawn from the tip of the measurement pipette tip via the measurement electrode; Measuring device with.
The tip side terminal of the measurement pipette tip is provided in the internal space of the measurement pipette tip
The measurement device according to claim 2, wherein the device-side terminal is provided in the chip mounting portion so as to contact the chip-side terminal of the measurement pipette chip mounted in the chip mounting portion.
The tip mounting portion has a shape that is fitted into an opening provided at the proximal end of the measurement pipette tip with a fixed positional relationship,
The apparatus side terminal is configured to be positioned with respect to the tip side terminal when the tip mounting portion is fitted into the opening of the measurement pipette tip with the predetermined positional relationship. The measuring device as described in 3.
The measuring apparatus according to any one of claims 2 to 4, further comprising a display unit on an outer surface for displaying a measurement result by the measurement circuit.
Attaching the measurement pipette tip according to claim 1 to the tip of the pipette;
Aspirating a sample solution from the tip of the measurement pipette tip, and bringing the sample solution into contact with a measurement electrode provided inside the measurement pipette tip;
Performing electrochemical measurement of the sample solution aspirated from the tip of the measurement pipette tip through the measurement electrode.
The measurement method according to claim 6, wherein the pipette is the measurement device according to any one of claims 2 to 5.