JP5011650B2 - Light detection method - Google Patents

Description

  The present invention relates to an optical sensor and an optical detection method for detecting a light emission state in a minute hole having a hole diameter of about 5 nm, for example.

Conventionally, as a method for sensing light, a light that strikes the sensing portion is sensed with high accuracy by forming a sensing portion in which an electronic state is changed by light on a semiconductor substrate. For example, the following Patent Document 1 exists as the prior art.
JP 2004-363354 A

  However, conventionally, there has been no technique for detecting a light emission state in a small hole such as a hole diameter of about 5 nm. Accordingly, an object of the present invention is to provide an optical sensor that detects a light emission state in a small hole having a hole diameter of about 5 nm, for example.

  To achieve this object, the present invention provides a plate made of semiconductor, first and second regions defined by the plate, and the first and second regions formed in the plate. At least one or more micro through holes and a measurement electrode provided in the first and second regions, and an electrolytic liquid or gel in the first and second regions and in the micro through holes. Filled.

  With this configuration, it is possible to provide an optical sensor that detects a light emission state in a small hole having a hole diameter of about 5 nm, for example.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a partially cutaway perspective view of an optical sensor of the present invention, and FIG. 2 is a sectional view thereof. 1 and 2, reference numeral 1 denotes a plate made of silicon, and a part of the plate 1 is a thin portion 2. Silicon, which is a material of the plate 1 and the thin portion 2, is a semiconductor having a desired electrical conductivity with a doping amount determined in advance in an arbitrary range. Furthermore, the first region 4 and the second region 5 are connected to each other only by the minute through hole 3 provided in the thin portion 2. Further, measurement electrodes 8 and 9 are installed in the first region 4 and the second region 5, respectively, and these measurement electrodes 8 and 9 are further connected to a measuring instrument (not shown). Furthermore, the insides of the first region 4, the second region 5, and the minute through-hole 3 are filled with an electrolytic liquid 10 such as sodium chloride or potassium chloride. The electrolytic liquid 10 may be an electrolytic gel. Further, caps 6 and 7 as an example of a cover plate are brought into contact with the first region 4 and the second region 5, whereby the first region 4 and the second region 5 are shielded from the external atmosphere. ing. At least one of the caps 6 and 7 is made of a material that transmits light from the outside.

  Here, as shown in FIG. 4, the equivalent circuit of the measurement system of the optical sensor in the present embodiment has a resistance R <b> 1 between the measurement electrodes 8 and 9 and the opening of the minute through hole 3. (13), R2 (14), the resistance Rh (15) in the minute through hole 3, the resistance Rp (16) in the plate, and the surface resistance Rs (17) transmitted through the wall surface of the minute through hole 3. Among these, R 1 (13), R 2 (14), and Rh (15) are determined by the conductivity of the electrolytic liquid 10, but the shape of the minute through hole 3 is larger than that of the first region 4 and the second region 5. Since it is overwhelmingly small, the relationship of Rh (15) >> R1 (13), R2 (14) is established, and the resistance between the electrodes is substantially parallel to Rh (15), Rp (16) and Rs (17). It depends on the circuit connected to. On the other hand, Rh (15), Rp (16), and Rs (17) are determined by the amount of impurities previously doped into silicon, which is the material of the thin portion 2.

  Next, a method for measuring the amount of light energy in the external atmosphere using the optical sensor of the present invention will be described. 3 and 5 are a sectional view and an enlarged sectional view showing a method of using the optical sensor of the present invention. Here, when the resistance value, which is an electrical characteristic value between the measurement electrodes 8 and 9 of the optical sensor of the present embodiment shown in FIG. 3, is measured, the resistance value is observed according to the equivalent circuit shown in FIG. .

  Next, as shown in FIG. 3, when light is introduced from the first region 4 side, the light passes through the electrolytic liquid 10 filling the first region 4 while being scattered, and as shown in FIG. It also enters the through hole 3. The light that has entered the minute through-hole 3 is also irradiated inside the minute through-hole 3. Here, the inner wall of the minute through hole 3 is made of silicon subjected to appropriate doping treatment, and the hole or electron mobility particularly near the inner wall surface of the minute through hole 3 is changed by light irradiation. This change is a change in the resistance Rs (17), and is detected as a change in the resistance value of the measurement electrodes 8 and 9.

When detecting a change in the resistance Rs (17), it is desirable that the values of Rh (15) and Rp (16) are the same as or larger than those of Rs (17). The hole diameter is reduced and the length in the longitudinal direction is increased .

  Moreover, since the optical sensor in this Embodiment has covered the 1st area | region 4 and the 2nd area | region 5 with the transparent caps 6 and 7 which are light transmittances, the 1st area | region 4 and the 2nd area | region 5 can be separated from the measurement environment.

  With the above configuration, even if the external atmosphere as a measurement environment is a liquid, light detection is performed with a very simple structure.

  In addition, when using the optical sensor in this Embodiment in a solution, appropriate protection is required so that the measurement electrodes 8 and 9 do not touch an external atmosphere solution, but this is omitted in the drawings. .

  In addition, the plate 1 and the thin portion 2 are made of a semiconductor, so that the hole or electron mobility in the inside and the surface of the plate 1 and the thin portion 2 can be controlled by the doping amount, but in particular a silicon or gallium arsenide substrate. In this case, there is a manufacturing advantage that the minute through hole 3 is easily formed in the thin portion 2.

  Further, the measurement electrodes 8 and 9 are made of silver, gold, platinum, or the like. Particularly, when the surface is coated with AgCl, the measurement electrodes 8 and 9 fill the first region 4 and the second region 5 with the electrolytic liquid 10. Since there is no electric double layer capacity between the two, a frequency component close to direct current can be easily measured, so that detection with higher accuracy is possible.

  It should be noted that it is desirable that several micro through holes 3 provided in the thin portion 2 are provided in order to accurately detect the resistance value between the measurement electrodes 8 and 9.

(Embodiment 2)
An optical sensor according to Embodiment 2 of the present invention will be described with reference to the drawings.

  As shown in FIG. 6, it can also be set as the structure which open | released one side of the plate 1 to the external atmosphere, In this case, the optical energy amount in a solution can be measured by attaching a photosensor to the electrolytic liquid 10 directly.

  FIG. 7 is a schematic cross-sectional view of an optical sensor according to another method of the second embodiment, and is characterized in that a suction means 18 is connected to the second region 5. The suction means 18 is a pressure reducing means such as a pump when the substance filling the first region 4 and the second region 5 is a solution, and is an electrolysis generating means when it is a gel. For example, when the suction means 18 is a pressure reduction means, the solution flows from the first region 4 side to the second region 5 side, and when the suction means 18 is an electrolysis generating means, an electrolytic substance in the gel, for example, Charged molecules, cells, and the like flow from the first region 4 side to the second region 5 side.

  With the above configuration, when minute particles or molecules (for example, cells, nucleic acids, proteins, etc.) flowing in the minute through hole 3 emit light, the light is detected on the inner wall of the minute through hole 3 by this light. Since the resistance Rs (17) decreases, the amount of energy emitted by these particles and molecules can be detected.

  The above detection method will be described with reference to FIG. Here, when light is detected by passing through a nucleic acid, protein, or the like that emits light through the micro through-hole 3, the nucleic acid sequence 19 is subjected to fluorescence to measure and evaluate an assay system in which the light emission state changes depending on the binding state of the sequence. After the modification, the nucleic acid sequence 19 is caused to flow into and out of the micro through-hole 3. With this configuration, the state in which the nucleic acid sequence 19 emits light can be detected with a simple structure and high accuracy. Furthermore, the nucleic acid sequence 19 usually has a long and narrow shape in a string state. When the hole diameter of the micro through-hole 3 is sufficiently small, the nucleic acid sequence 19 passes in an extended state as shown in the figure. If the assay system is configured such that only the specific sequence portion of the nucleic acid sequence 19 emits light, the surface resistance Rs (17) changes only when the specific sequence portion passes, so the position of this specific sequence in the nucleic acid sequence 19 Can be measured.

  Furthermore, as shown in FIG. 9, when the particles that pass through the micro through-hole 3 are the cells 20, the cells 20 are used as an assay system in which the cells emit light by reaction with a specific chemical substance, and this light is detected. Thus, the reaction state between the cell 20 and a specific chemical substance can be known.

  As described above, since the light emission state of particles or molecules is measured in an extremely small hole, the light emission state of individual particles or molecules can be measured with high accuracy.

  As described above, the optical sensor according to the present invention can detect a light emission state in a small hole having a hole diameter of about 5 nm, for example.

1 is a partially cutaway perspective view of an optical sensor according to Embodiment 1 of the present invention. Cross section of the same light sensor Sectional view showing how to use the same optical sensor Equivalent circuit diagram of the same optical sensor FIG. 3A is an enlarged cross-sectional view showing how to use the optical sensor. Sectional drawing of the optical sensor in Embodiment 2 of this invention Sectional drawing of the optical sensor in Embodiment 2 The expanded sectional view which shows the usage method in Embodiment 2 The expanded sectional view which shows the usage method in Embodiment 2

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate 2 Thin part 3 Micro through-hole 4 1st area | region 5 2nd area | region 6 Cap 7 Cap 8 Measuring electrode 9 Measuring electrode 10 Electrolytic liquid 13 Resistance R1
14 Resistance R2
15 Resistance Rh
16 Resistance Rp
17 Resistance Rs
18 Aspiration means 19 Nucleic acid sequence 20 cells

Claims (3)

A plate made of a semiconductor, first and second regions partitioned by the plate, at least one or more micro through-holes formed in the plate and connecting the first and second regions, and Measuring electrodes provided in the first and second regions, and using the optical sensor in which the first and second regions and the micro through-holes are filled with an electrolytic liquid or gel. Mixing the particles or molecules that emit light by a specific external stimulus or an assembly thereof into the electrolytic liquid or gel in the region, and the particles or molecules from the first region to the second region Alternatively, the step of causing these aggregates to flow out and the electrical property value between the measurement electrodes installed in the first region and the second region are examined, whereby the particles or molecules or the Light detecting method characterized by having a step of detecting the light these aggregates emitted. Particles are cells, and the stimulation was due to chemicals, light detecting method according to claim 1, wherein the sensing light that cells that have undergone the stimulus is emitted. The light detection method according to claim 2 , wherein the molecule is a nucleic acid or a protein, and the stimulus is excitation light, and light emitted from the molecule receiving the excitation light is sensed.

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