KR20060025792A - System for measuring number of bacteria in sample water and method of forming a device for the system - Google Patents

Abstract

A water quality measurement system capable of detecting bacterial counts and a method for forming the core device thereof are disclosed.

The water quality measurement system of the present invention consists of a prototype device in which a glass substrate is microfabricated and bonded with a femtosecond laser, a pump 10 for injecting a sample into a processed detection device, and a diode as a light source for bacterial detection. A photodetector using a laser 11 and measuring a signal of bacteria by a laser light source is provided with a photo multiplier tube (PMT) 12 and a microprocessor 13 for performing calculations using the measured signal.

 The present invention introduces microfluidics-based technology, which is applied in the medical field, to the development of a device for detecting bacterial counts, thereby miniaturization and movement due to the integration of a measurement system, and maintains performance for a long time. There is an advantage of using a glass substrate to be able.

Femtosecond laser, water quality analysis, bacterial detection

Description

System for measuring number of bacteria in sample water and method of forming a device for the system

1 is a block diagram of a laser processing apparatus for forming a device of the present invention;

2 is an explanatory diagram schematically showing a device structure of the present invention and a method of forming the same;

3 is a schematic view showing the configuration of a water quality measurement system capable of detecting the number of bacteria of the present invention;

Figure 4 is a graph of the measurement result of the standard sample using the system of the present invention,

Figure 5 is an analysis graph obtained to know the number of bacteria through the measurement result of Figure 4

<Explanation of symbols for the main parts of the drawings>

1: computer

2: femtosecond laser

3: galvano scanner 31: controller 32: reflector

4,5,6: glass substrate 51: channel 53,55: sample passage 57: optical path

7: optical fiber

8: Capillary

9 device for measurement

10: sample supply unit 101: syringe 103: micro pump

11: diode laser

12: PMT (Photo Multiplier Tube)

13: microprocessor

The present invention relates to a water quality measurement system and a method for forming a device used therein, and more particularly, to a water quality measurement system capable of measuring the number of bacteria in water and a device formation method used therein.

The demands and restrictions on food safety testing in group and school meal facilities are becoming stronger. However, at present, many catering establishments or companies do not have a pre-inspection because an inspection method or an inspection apparatus that can perform an efficient inspection at an appropriate cost has not been developed.

In addition, water quality management, particularly risk management, is important in modern hog and other livestock industries. Hazards to water can be broadly classified into microbiological and chemical factors. Feces are the most common source of pathogens that can harm livestock. Basically, livestock farmers need to provide water that is not contaminated with feces, and for this purpose, a means of confirming that the water consumed by livestock is not contaminated with feces is required.

All livestock pathogens that can be transmitted through feces can be tested with a water sample, but the cost is very high. Normally, water contaminated with feces contains E. coli, enterobacteria, fecal streptococci, and the like. These bacteria are collectively known as indicators of feces. Therefore, the water quality test to check the indicator of the feces can determine whether the water is contaminated with feces. Typically, water used in farms should be evaluated for total microbial counts as an assessment of overall water quality and fecal contamination. In addition, even when such an evaluation is made, an attribution test is absolutely required.

In addition, the dependence on the storage tank is deepening due to the rapid increase in the group accommodation. As for microbial drinking water pollution, it is urgently required to develop appropriate drinking water pollution measurement technology at the national level in terms of national security.

However, water pollution measurement and other water quality analysis are now in a centralized form. In this type of measurement and analysis environment, a reaction time of 5 days or longer is required for water quality inspection and organic matter detection in the water. And this work is being done in laboratory-type measurement systems. Therefore, there is a problem that it is impossible to implement a real-time measurement and remote monitoring system.

On the other hand, the water quality measurement device used in the past used a resin product, they have a problem of increasing the cost of water quality measurement because it is used for a single use or only for a short period of durability is poor.

The present invention is to solve the above problems, bacterial water detection and water quality that enables the real-time preliminary experimental test and monitoring of drinking water for the prevention of water pollution accidents such as group residential facilities, such as apartments and group meals or school meal facilities It is an object to provide a method of forming a measuring system and a device used therein.

The present invention also provides a bacterial water detection and water quality measurement system and a device for use in addition to a wastewater facility relating to the treatment of sewage and livestock wastewater, which can be carried out at a low cost whether the discharged wastewater meets legal standards. It is an object to provide a method.

The present invention can secure the reliability of the test even through the simple measurement of the sub-unit population in the sampling and analysis method of water pollutants, and the bacteria number detection and water quality measurement system that can be easily used by the general public, and It is an object to provide a device forming method.

Bacterial number detection and water quality measurement system for achieving the above object is a measuring device in which a light path is formed so as to guide the light of the light source in at least a channel and the channel specific section of the glass substrate, the light path of the device A light source for supplying a light source for supplying a sample to a channel of the device, a sample supply unit for supplying a sample to a channel of the device, and measuring a bacterial signal generated by the action of bacteria on the light emitted from the light source, and converting the light into an electrical signal and outputting the light. And a processor for processing the electrical signal to determine the number of bacteria.

In the present invention, the measuring device preferably has an inlet sample passage and an outlet sample passage formed in the glass substrate so as to be connected to both ends of the channel. In addition, since each sample passage is connected through a sample supply unit and a capillary, it is generally preferable that the sample passage be larger than the size of the channel. Similarly, the optical path is generally formed larger than the channel size when the optical fiber is embedded to guide the light of the light source.

In the present invention, a photomultiplier tube (PMT) may be used as the photodetector. PMT is a glass vacuum tube that generally includes an optical sensor called a photocathode and generates electrons according to the amount of light received by the optical sensor. These electrons are converted to an electrical analog signal through a secondary radiation process, which is converted back into a digital signal and output.

In the present invention, the sample supply unit is typically provided with a micro syringe and a micro pump coupled to the micro syringe. In addition, the micro pump is preferably configured to be connected to the processor of the present invention so that its discharge can be adjusted.

On the other hand, in order to achieve the above object, a method for forming a device for detecting a bacterial number and measuring a water quality measurement system includes inputting a position and a size of a structure including a channel and an optical path to be formed on a substrate into a computer, The glass substrate is placed, and the femtosecond laser is operated while the galvanometer is operated by giving a program operation signal from the computer to the galvanometer regulator as an output device connected to the computer to operate the glass substrate.

At this time, each structure such as a channel on the glass substrate is formed by a method of forming a groove by irradiating a laser beam to a specific portion of the substrate to make a groove. Since the width and depth of each structure can be different, the laser beam irradiation can be repeated at the same position or changing positions depending on the area.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of an embodiment of a laser processing apparatus for forming a device of the present invention, and FIG. 2 is an explanatory diagram schematically showing the device structure of the present invention and a method of forming the same. ,

The manufacturing techniques or manufacturing steps required for the method of the present invention can be divided into three broad categories. The first is to perform fine processing on the surface of the glass substrate using a femtosecond laser. The second is to connect the capillary and the optical fiber for the sample input and discharge to the inlet and outlet sample passage leading to the channel. And, the third step is to cover and combine the other glass substrate on the glass substrate on which the channel is formed, packaging.

Referring to the first step of forming a device of the present invention with reference to Figure 1, a device processing apparatus using a femtosecond laser for fabricating the present invention, the femtosecond laser (2), the reflector 32 for changing the path of the laser beam and the controller The galvano scanner 3 which is usually provided with 31 is provided, and the computer 1 which adjusts the trajectory of a laser beam by adjusting a galvano scanner according to the designed form.

The glass substrate 4 is placed on a separately provided stage of the processing apparatus as shown in FIG. Each structure of the device, drawn in the computer 1 with a program such as computer aided disign (CAD), is embodied on the glass substrate 4 via a laser beam moving in accordance with a computer signal such as an output command for drawing. That is, when the computer 1 signal goes to the controller 31, the controller sends an adjustment signal for adjusting the reflector 32 of the galvanometer 3. In the galvanometer (3), each axis controller responsible for the x-axis and y-axis adjustment on the plane receives the control signal to move the reflector (32).

The movement of the reflector 32 determines the irradiation position of the laser beam on the glass substrate 4. Therefore, the glass substrate 4 is fused on the glass substrate 4 by laser beam processing, and the groove-like structure of the device as previously drawn by CAD is formed.

1 and 2, the focal size of the femtosecond laser 2 may be up to several micrometers, and thus the width of the grooves to be formed on the glass substrate 5 may be several micrometers. However, in consideration of the size of the bacteria, and in consideration of the size of the sample can easily flow in the channel 51, it is preferable to form the channel size of the device to 10 micrometers or more and 100 micrometers or less.

Meanwhile, the sample passages 53 and 55 and the optical path 57 formed at this time may be 100 to several hundred micrometers in consideration of the size of the capillary 8 or the optical fiber 7 connected to the inlet. To make this structure with a laser beam with a focal size of only a few micrometers, the laser beam for processing the glass substrate 5 must be passed repeatedly at the same position or repeatedly at a fine distance shift. Can be.

The width and depth of the channel can be increased to the appropriate size by increasing the number of times the laser beam passes. In the glass substrate 5 having the structure thus made, the channel 51 and the like may be separately modified to introduce a hydrophilic group through surface treatment.

Referring to FIG. 2, after the glass substrate 6 is bonded to each other on the glass substrate 5 processed as described above, the sample is easily blocked without blocking the inlet and outlet passages 53 and 55 of the sample. Capillary 8 is joined to flow. Welding may be used for the joining, but usually an adhesive is used.

In addition, a single mode optical fiber 7 for guiding a diode laser beam of 532 nm so that the bacteria in the sample receives the light of the light source and emits a bacterial signal by fluorescence or scattered light is inserted into and adhered to the optical path 57. This creates a measuring device.

The process of bonding the two glass substrates 5 and 6 to each other and bonding the capillary 8 or the optical fiber 7 to the glass substrates 5 and 6 may be performed in a different order.

Figure 3 is a schematic diagram showing the configuration of a water quality measurement system capable of detecting the number of bacteria of the present invention.

Referring to FIGS. 2 and 3 together, the optical fiber introduced at the optical path inlet of the measuring device meets a channel at one end to form a T-shaped portion. In the T-shaped portion formed at the position where the channel 51 and the optical path 57 formed in the device meet with respect to the measuring device 9 formed as shown in FIG. . That is, the photodetector is placed so as to be substantially perpendicular to the direction in which the light that excites the sample is irradiated.

The other end of the capacitor 8, which is connected to the inlet passage 53 of the measuring device 9, is connected to the micro syringe 101 of the sample supply part 10. The micro syringe 101 supplies the sample to the channel 51 of the measuring device 9 by adjusting the flow rate of the coupled micro pump 103. The sample is discharged through the capillary of the outlet sample passage 55 through the section where the channel 51 meets the optical path 57 and is measured.

The photodetector is connected to a high voltage power source, and recognizes the bacterial signal detected in the observation portion and outputs it as an electrical signal. Photomultiplier tube (PMT) is used as the photodetector. PMT is a glass vacuum tube that generally includes an optical sensor called a photocathode and generates electrons according to the amount of light received by the optical sensor. These electrons go through a secondary radiation process and output an electrical analog signal or a digital signal converted from the analog signal.

The output signal is input to the counter via a signal operating section consisting of a conventional signal converter, a signal expander, a signal comparator, and the like. As shown in FIG. 4, when a voltage peak equal to or greater than a predetermined threshold voltage is recognized as one bacterium, the counter accumulates the number and measures the number of bacteria.

The number of bacteria measured is input to the microprocessor 13 to determine the number of bacteria per unit sample amount in consideration of the amount of sample that flows for a certain time. In order to control the amount of sample flowing for a certain time, the microprocessor 13 is preferably connected to the micro pump 103 of the sample supply unit 10. That is, the micro pump 103 is preferably configured to be connected to the microprocessor 13 so that its discharge can be adjusted.

The method of capturing the bacterial signal in the photodetector will be described further. First, the laser beam guided by the diode laser 11 is irradiated to the flowing sample through the optical fiber 7. Bacteria having their own fluorescent material fluoresce the laser light, and the photodetector detects the fluorescence. The photodetector may be manufactured to measure quantitatively the number of bacteria contained in the sample by measuring scattered light with respect to particulate components of bacteria that do not receive their own light. In addition, if the characteristics of fluorescence can be distinguished, it is also possible to obtain a numerical value for each type of bacteria.

FIG. 5 is an analysis graph obtained to determine the bacterial number level through the measurement result of the system of FIG. 4.

This graph shows the results of measuring bacterial signals per hour by varying the sample volume per hour for a standard sample with three concentrations, each representing a linear relationship. This result shows the reliability and measurable concentration range of the quantitative measurement of the system of the present invention.

More specifically, the horizontal axis of the graph shows the amount of sample flowing per hour, and the vertical axis shows the number of bacterial signals per hour. Therefore, the relationship between the amount of longitudinal axis and the amount of abscissa with respect to the same sample becomes a directly proportional relationship, and theoretically has a constant slope. Since the slope is the amount of vertical axis divided by the amount of horizontal axis, it becomes the number of bacteria signals per sample, indicating the bacterial density of the sample.

According to the present invention, since the measuring device can be produced at low cost and used durably, real-time water quality measurement can be made at each workplace or farm where bacterial count testing is required at a low cost. This real-time water quality inspection and monitoring is essential for the stable management of water quality hazards.

 The present invention introduces microfluidics-based technology, which is applied in the medical field, to the development of a device for detecting bacterial counts, thereby miniaturization and movement due to the integration of a measurement system, and maintains performance for a long time. There is an advantage in that it is possible to measure inexpensive water quality by using a glass substrate.

In addition, by attaching a wired or wireless communication module to the measurement system using the device according to the method of the present invention, it is possible to monitor at a remote location, and in particular, remote monitoring can be easily performed where a monitoring system such as a central control room is required. .

And, compared to the existing water quality analysis method to leave the sample for a long time to determine the degree of water contamination by organic matter by measuring DO, BOD, COD, etc. The system of the present invention can directly measure the number of bacteria in real time Can be.

Claims (9)

A measuring device in which a light path is formed on the glass substrate so as to guide light of a light source in at least a channel and a specific region of the channel, A light source for supplying light to the optical path of the device, A sample supply unit supplying a sample to a channel of the device, A photodetector for observing the channel specific section to measure a bacterial signal generated by the action of bacteria on the light irradiated from the light source, and converting it into an electrical signal and outputting the same; And a processor for determining the number of bacteria by processing the electrical signal. The method of claim 1, The measuring device is provided with an inlet side sample passage and an outlet side sample passage formed in the glass substrate so as to be connected to both ends of the channel, Wherein each sample passage is formed larger than the size of the channel so as to be connected through a sample supply unit and a capillary. The method of claim 1, The optical path is provided with an optical fiber for inducing light of the light source, One end of the optical fiber is connected to a laser device. The method of claim 1, Photomultiplier tube (PMT) is used as the photodetector, characterized in that the bacterial number detection and water quality measurement system. The method according to claim 1 or 2, The sample supply unit comprises a micro syringe and a micro pump coupled to the syringe, characterized in that the bacteria number detection and water quality measurement system. The method of claim 1, The micro-pump is connected to the microprocessor and configured to control its discharge rate, the bacterial count detection and water quality measurement system. Programmatically inputs the position and size of the structure including the channel and the optical path to be formed on the substrate into a computer, A method of forming a device for measuring bacterial counts and water quality measurement systems, comprising: placing a glass substrate in a predetermined area, operating a femtosecond laser, and operating the galvanometer with an output device connected to a computer to process the glass substrate. The method of claim 7, wherein Each structure on the glass substrate is formed by a method of forming a groove by receiving a femtosecond laser beam and blasting it. The method of claim 8, Wherein each structure repeatedly forms the femtosecond laser beam irradiation at the same position or while changing positions according to the width and depth to be formed.

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