JP7174741B2 - Micro-sampling chip and inspection device using the micro-sampling chip - Google Patents

Description

The present invention is useful for conducting environmental tests such as heavy metal measurements, biochemical tests such as urine test strips, clinical tests, and food tests such as detection of residual pesticides. The present invention relates to a microsampling chip and its inspection device.

Heavy metals such as cadmium, cobalt, mercury, copper, zinc, and lead are harmful to the human body, and it is very important to know the amount of heavy metals contained in water and soil. Various methods have been proposed and implemented as methods for measuring heavy metals (see Patent Documents 1 and 2). In addition, the problem of residual pesticides caused by spraying pesticides on food such as grains, vegetables, and fruits is serious, and in 2013, 23 children died in India due to monocrotophos residues in vegetables. something serious is happening.

In the field of medical care and food inspection, it is important to be able to perform necessary inspections accurately on the spot in order to ensure subsequent diagnosis, prevention, and peace of mind. Being able to detect the disease, food safety, and the presence or absence of pesticide residues on the spot by testing in a matter of minutes allows patients to be diagnosed and prescribed medicines as soon as possible, and for drinking water and food, can guarantee the safety of

Test papers in which color reagents are immobilized on paper media such as filter paper are commonly used to test specific substances in human urine or blood, immunoassays, tests for residual pesticides, and tests for soil contamination. However, no technique has been established to enable simple and rapid inspections on site using test papers.

JP-A-11-174054 JP 2009-034041 A Patent No. 6677273

Electrochemical measurements and tests using test paper are performed by bringing the sample into contact with the sensor part such as the measuring electrode or test paper. It is an important factor for reproducibility. Therefore, it is necessary to control the sample amount with high accuracy. In particular, when using a small amount of sample such as several tens of μL, a precision of 0.1 μL is required, and it is difficult to control such a high-precision sample volume with an inexpensive pipette. In testing methods in which a small amount of sample is dropped onto an electrode or test paper exposed to air, sample concentration may change during testing due to evaporation of the sample into the air.

In addition, a disposable tip is attached to the tip of a pipette used for testing a certain amount of sample to prevent contamination. It cannot be said that contamination is reliably prevented. On the other hand, an inspection method in which a sensor portion is immersed in a sample placed in a container for measurement cannot obtain quantitative properties of the amount of sample that contacts the sensor. Diffusion occurs due to the influence of charge and heat on the surface of the sensor portion, and this influence causes a change in the surface concentration of the sample, resulting in a problem of reduced reproducibility of measured values.

Patent Document 3 (Japanese Patent No. 6677273) discloses a technique relating to a microsampling chip having a pump function, and the above problem can be solved by using the disclosed microsampling chip. On the other hand, this technique has room for improvement in the ease of manufacturing the microsampling chip and the quantification of the amount of sample inhaled.

SUMMARY OF THE INVENTION An object of the present invention is to provide a micro-sampling chip that is easy to manufacture while having a pumping function and that has good quantification of sample suction amount.

A microsampling chip according to the present invention has a distal end and a proximal end, the distal end is provided with a suction port for suctioning a liquid sample, and the suction channel extends from the distal end toward the proximal end. a chip body having a holding space in fluid communication with the suction port through a chip body; for aspirating sample into the holding space from the inlet when the one end is fixed to the tip body and is in fluid communication with the holding space, and the distance between the one end and the other end increases. and a sensor unit, at least a part of which is provided to come into contact with the sample sucked into the holding space, wherein the pump unit includes the One end faces the same direction as the distal end of the tip body and the other end faces the same direction as the proximal end of the tip body, and the other end of the pump section is provided at the proximal end of the tip body. is exposed.

In the first aspect of the microsampling chip according to the present invention, the pump part is a cylindrical member having a circular cross section perpendicular to the direction of expansion and contraction, and the diameter of the cross section before and after expansion and contraction is They are almost identical. In the case where the pump part has a shape such as a sphere or a hemisphere, even if the pump part is released from the pressure after being compressed by pressing the pump part, the state in which the pump part is compressed and crushed may change from the state before compression. A situation may arise in which the state of On the other hand, by making the pump section a cylindrical member whose cross-sectional diameter does not change before and after expansion and contraction, it is possible to prevent the pump section from returning to its pre-compression state after being crushed. less likely to occur.

An example of such a pump section is a bellows pump.

In a second aspect of the micro-sampling chip according to the present invention, the base end of the chip body is provided with a recess spatially separated from the holding space, and the main portion of the pump portion excluding the one end is provided. is accommodated in the recess. In this manner, since the pump section is not exposed, it is possible to easily prevent a situation in which an object collides with the pump section from the side, thereby facilitating handling of the micro-sampling chip. Further, since the base end of the micro-sampling chip is provided with the concave portion, it becomes easy to hold the base end of the micro-sampling chip.

In a third aspect of the micro-sampling chip according to the present invention, the sensor section is provided with a plurality of electrodes for performing electrochemical measurement of a sample, and the wall surface on the base end side defining the holding space is substantially vertical. one end of the electrode substrate is arranged in the holding space, and the other end of the electrode substrate is arranged at the proximal end of the chip body so as to be accessible to each electrode of the electrode substrate. It is exposed at the proximal end of the tip body. Such an aspect makes it possible to easily perform electrochemical measurement of a sample using the microsampling chip.

An inspection device according to the present invention includes the above-described microsampling chip, and an inspection device main body that detachably holds the proximal end of the microsampling chip. In the inspection apparatus, the inspection apparatus body has a pump drive for temporarily pushing the end surface of the pump portion exposed at the base end of the micro-sampling chip toward the tip side of the micro-sampling chip by a fixed amount. and a measurement unit that measures the sample sucked into the holding space of the micro-sampling chip using the sensor unit provided in the micro-sampling chip.

The micro-sampling chip according to the present invention realizes a unique pump function by mounting a pump unit, so that high quantitativeness of the amount of sample sucked into the holding space can be obtained. Further, it is possible to form the present microsampling chip by separately forming the chip body and the pump section and then bonding the pump section to the chip body. Then, since the chip main body and the pump section can be easily formed by resin molding, it is easy to manufacture the present microsampling chip.

Since the inspection apparatus according to the present invention uses the micro sampling chip of the present invention, which is easy to manufacture and has high quantitativeness of the sample inhaled amount, it is possible to easily realize an apparatus with high inspection accuracy.

1 is a perspective view showing one embodiment of a micro-sampling chip; FIG. It is sectional drawing of the same Example. 1 is a schematic cross-sectional configuration diagram showing an embodiment of an inspection device provided with a micro-sampling chip; FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a microsampling chip and an inspection device according to the present invention will be described below with reference to the drawings.

An embodiment of the microsampling chip will be described with reference to FIGS. 1 and 2. FIG.

The micro-sampling chip 1 of this embodiment is attached to the tip of an inspection device main body 100 (see FIG. 3), which will be described later, and constitutes the inspection device together with the inspection device main body 100. FIG. The microsampling chip 1 includes a chip body 2, a pump section 4 and an electrode substrate 6 (sensor section).

The tip body 2 has a distal end (lower end in FIG. 2) and a base end (upper end in FIG. 2), and has a suction port 8 for sucking a sample at the distal end. Inside the tip body 2 are a suction channel 10 extending from the distal end of the tip body 2 toward the proximal end, a holding space 12 fluidly communicating with the suction port 8 via the suction channel 10 , and a horizontal space from the holding space 12 . A connection channel 14 extending in the direction is provided. A cylindrical recess 16 is provided at the proximal end of the tip body 2 .

The pump part 4 is accommodated in the recess 16 of the tip body 2 . The pump part 4 has one end 4a (lower end in FIG. 2) and the other end 4b (upper end in FIG. 2). facing the same direction as the edge. The pump portion 4 is a substantially cylindrical bellows pump in which the distance between one end 4a and the other end 4b is elastically expanded and contracted. Although the volume of the internal space of the pump part 4 changes before and after expansion and contraction, the diameter of the cross section perpendicular to the expansion and contraction direction does not substantially change. The pump part 4 is made of plastic such as polyethylene. One end 4a of the pump portion 4 is fixed to the chip body 2 while being fluidly connected to the connection channel 14 from above. The pump part 4 does not necessarily have to be a bellows pump, and the distance between the one end 4a and the other end 4b can be elastically expanded and contracted, and the diameter of the cross section perpendicular to the expansion/contraction direction is substantially the same before and after expansion/contraction. It can be anything as long as it exists.

The other end 4b of the pump portion 4 is exposed at the base end of the tip body 2, and the inner space of the pump portion 4 is filled by pressing the other end 4b of the pump portion 4 from the base end side of the tip 2 toward the tip. can be reduced. When the pressure on the other end 4b is released after the internal space of the pump portion 4 has been reduced, the other end 4b of the pump portion 4 returns to its original position due to its own elastic force, thereby reducing the internal space of the pump portion 4. Expand. When the internal space of the pump portion 4 expands, a suction force is generated that draws the fluid from the suction port 8 toward the holding space 12 . Thereby, the sample can be sucked from the tip of the suction port 8 and the sucked sample can be held in the holding space 12 .

The electrode substrate 6 is a flat plate having a plurality of electrodes for electrochemical measurement of a sample formed on its surface or inner surface. The electrode substrate 6 penetrates substantially perpendicularly through a wall surface located on the base end side of the chip body 2 among the wall surfaces defining the holding space 12 . is exposed at the proximal end of the chip body 2, and each electrode formed on the electrode substrate 6 at the proximal end of the chip body 2 can be electrically accessed.

When the sample is introduced into the holding space 12 by driving the pump section 4, one end of the electrode substrate 6 comes into contact with the sample. In this state, by applying a required voltage to each electrode of the electrode substrate 6 and measuring the current flowing between predetermined electrodes, the sample can be electrochemically measured. The space from the suction port 8 of the tip body 2 to the pump section 4 is sealed except for the suction port 8, so that the sample sucked from the suction port 8 does not leak from the proximal end side of the tip body 2.

An embodiment of an inspection apparatus using the microsampling chip 1 will be described with reference to FIG.

The inspection device is composed of the microsampling chip 1 and the inspection device body 100 . The microsampling chip 1 is disposable, and one microsampling chip 1 is attached to the tip of the inspection apparatus main body 100 for each sample and used.

The inspection device main body 100 has a chip holding part 102 for holding the microsampling chip 1 at its tip. In this embodiment, the tip holding part 102 is a hollow cylindrical projection provided on the front end surface of the inspection apparatus main body 100 . The outer diameter of the chip holding portion 102 is substantially the same as the inner diameter of the concave portion 16 at the proximal end of the microsampling chip 1 . Friction between the inner surface of the concave portion 16 and the outer peripheral surface of the chip holding portion 102 keeps the micro sampling chip 1 attached to the tip of the inspection apparatus main body 100 . The structure for holding the microsampling chip 1 in the inspection apparatus main body 100 is not limited to such an aspect, and any structure may be used as long as the microsampling chip 1 is detachably held at the tip of the inspection apparatus main body 100. It may be a structure.

The inspection device main body 100 further includes a pressing rod 104 , a driving mechanism 106 , an insertion slot 108 , a terminal 110 and a measuring portion 112 . The pressing rod 104 moves in the extension/contraction direction of the pump section 4 (vertical direction in the drawing) at the tip of the inspection apparatus main body 100 to press the pump section 4 of the microsampling chip 1 . The driving mechanism 106 is for driving the pressing rod 104 using a stepping motor or the like.

The insertion slot 108 is provided so that when the micro-sampling chip 1 is attached to the distal end of the inspection device main body 100, the proximal end portion (upper end portion in the drawing) of the electrode substrate 6 of the micro-sampling chip 1 is inserted. It is The terminals 110 are exposed on the inner surface of the insertion slot 108 , and when the electrode substrate 6 is inserted into the insertion slot 108 , the terminals 110 are in electrical contact with the electrodes formed on the electrode substrate 6 . It's like

A measuring section 112 is electrically connected to the terminal 110 . The measurement unit 112 is an electric circuit for applying a voltage to a predetermined electrode of the electrode substrate 6 via the terminal 110 to perform electrochemical measurement of the sample.

As described above, the micro-sampling chip 1 itself is provided with the pump unit 4, thereby realizing a pump function independent of the inspection device main body 100. After inhaling the sample from the suction port 8 of the micro-sampling chip 1, The sample to be measured does not adhere to the inspection device main body 100 in any posture of the device. This prevents sample contamination.

In addition, since the pump portion 4 realizes a pump function unique to the micro-sampling chip 1, stress is less likely to act on the chip main body 2 of the micro-sampling chip 1 when the pump is operated. Deformation of the chip body 2 due to pressure is suppressed, and a situation in which the microsampling chip 1 is damaged is less likely to occur. Furthermore, the microsampling chip 1 can be easily formed by manufacturing the pump section 4 separately from the chip body 2 and then adhering it to the chip body 2 . Since the chip body 2 and the pump section 4 can be manufactured at low cost by resin molding, the microsampling chip 1 can be manufactured at low cost.

Although the electrode substrate 6 is provided as the sensor section in the above embodiment, the present invention is not limited to this. For example, at least one colorant that exhibits a coloration reaction according to the components in the sample upon contact with the sample may be arranged in the holding space 12 as a sensor unit. In this case, the inspection apparatus main body 100 includes a camera for capturing the degree of coloration of the colorant arranged in the holding space 12, and the degree of coloration of the colorant based on the captured image of the camera using RGB or the like. and a calculation unit for digitizing.

REFERENCE SIGNS LIST 1 micro-sampling chip 2 chip body 4 pump section 4a one end of pump section 4b other end of pump section 6 electrode substrate 8 suction port 10 suction channel 12 holding space 14 connection channel 16 concave portion 100 inspection device main body 102 chip holding portion 104 pressing Rod 106 Drive Mechanism 108 Insertion Slot 110 Terminal 112 Measuring Part

Claims (2)

An inspection device comprising an inspection device main body and a micro sampling chip attached to the tip of the inspection device main body,
The microsampling chip is
It has a distal end and a proximal end, the distal end is provided with a suction port for suctioning a liquid sample, and fluid communication is provided with the suction port via a suction channel extending from the distal end toward the proximal end. a chip body with a holding space;
It has one end and the other end, the volume of the internal space is changed by elastic expansion and contraction of the distance between the one end and the other end, and the one end is fixed to the tip body to form the holding space. a bellows pump in fluid communication with and configured to generate a suction force for drawing sample from the suction port into the holding space when the distance between the one end and the other end increases;
a sensor unit, at least a portion of which is provided so as to come into contact with the sample sucked into the holding space;
The bellows pump is provided so that the one end faces the same direction as the distal end of the tip body and the other end faces the same direction as the proximal end of the tip body, and the bellows pump is provided at the proximal end of the tip body. the other end of the bellows pump is exposed ,
The inspection device main body has a hollow cylinder-shaped protrusion on its distal end surface, and the micro sampling chip is spatially separated from the holding space at the base end of the tip main body, and the microsampling tip of the inspection device main body A recess is provided to fit the projection, and the micro sampling chip is attached to the tip of the inspection device body by fitting the projection of the inspection device main body into the recess of the chip body, and the bellows pump is operated. is accommodated in the recess of the tip body,
The inspection device body includes:
a pump driving unit for performing an operation of temporarily pushing the other end of the bellows pump exposed at the base end of the microsampling chip toward the distal end of the microsampling chip by a fixed amount;
and a measuring unit that measures the sample sucked into the holding space of the micro sampling chip using the sensor unit provided in the micro sampling chip . The sensor unit is an electrode substrate provided with a plurality of electrodes for performing electrochemical measurement of a sample and penetrating substantially perpendicularly through a wall surface on the base end side that defines the holding space, and one end of the electrode substrate is The electrode substrate is arranged in the holding space, and the other end of the electrode substrate is exposed at the proximal end of the chip body so as to be accessible to each electrode of the electrode substrate at the proximal end of the chip body. Item 1. The inspection device according to item 1.

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