CN102147365A - Handheld bioluminescent detector and detection method - Google Patents

Abstract

The invention relates to a handheld biological fluorescence detector and a detection method. It is characterized in that the handheld instrument includes: an optical detection module 1 , a signal acquisition module 2 , a signal processing module 3 , a signal display and transmission module 4 and a power supply module 5 . The detection method of the handheld instrument is characterized in that: the optical detection module 1 converts the bioluminescent signal to be detected into an electrical signal, and the electrical signal is transmitted to the signal processing module 3 through the signal acquisition module 2, and the signal processing module completes the display and transmission of the results task, and provide feedback control quantity to the optical detection module 1 at the same time. The power supply module 5 is used to provide suitable working voltages to the above-mentioned modules. Using the detector and the detection method of the invention can effectively solve the traditional problem that the hand-held instrument is difficult to detect weak fluorescent signals.

Description

A hand-held bioluminescence detector and detection method

technical field

The invention relates to a handheld biological fluorescence detector and a detection method. The detection method and instrument provided by the invention can be used for highly sensitive detection and analysis of weak biological fluorescence, and belong to the technical field of advanced manufacturing and automation.

Background technique

Fluorescence detection technology is a commonly used detection technology in analytical chemistry. This technology uses the fluorescence induced by certain substances (after being excited) to reflect the characteristics of the substance for qualitative or quantitative analysis. At present, fluorescence detection technology has been widely used in biology, analytical chemistry, exploration and environmental monitoring and other fields. In these fields, commonly used fluorescence and analytical detection instruments include: fluorescence microscope, confocal fluorescence microscope, fluorescence spectrophotometer and fluorescence spectrometer. However, these instruments are often single-function, bulky and not portable, which cannot meet the rapid real-time detection of complex field samples outdoors. At the same time, the bioluminescent signals in the environment are often complex: the intensity of the fluorescence varies greatly, and the spectral range of the fluorescence is wide (the characteristic peaks of different samples are different).

The photoelectric conversion module that converts the fluorescent light intensity in a specific wavelength range into an electrical signal is one of the key technologies to realize the handheld fluorescence detection process. In recent years, miniaturized photoelectric conversion devices have emerged one after another, including phototubes, photodiodes, and the like. At present, these photoelectric conversion modules are used to make hand-held bacteria count detectors, such as Hygiena's SystemSURE series products using photoelectric cells. However, the dark current of photocell and photodiode is relatively large, especially their sensitivity is low, and the fluorescent signal to be detected is often relatively weak, which limits the detection performance and application range of the instrument. Photomultiplier tube (Photomultiplier Tube, PMT) is a photodetection device with extremely high sensitivity, low noise and ultra-fast time response. Combining miniaturized photomultiplier tubes with appropriate optical and electrical modules makes a handheld fluorescence detection system possible. However, there is no example of using miniaturized photomultiplier tubes to make a handheld fluorescence detection system. The invention provides a hand-held instrument for biological fluorescence detection. The instrument integrates a miniaturized photomultiplier tube and combines appropriate optical and electrical modules to meet the rapid and real-time fluorescence detection of complex outdoor samples.

Contents of the invention

The purpose of the present invention is to provide a hand-held bioluminescence detector and detection method, the bioluminescence detection method can be used for bioluminescence signal (the luminous flux of fluorescence signal is at 1 picolumen～1 millilumen, the spectrum of bioluminescence signal Range 300nm ~ 750nm) detection.

The purpose of the present invention is achieved by the following measures: the handheld bioluminescent detector includes an optical detection module, a signal acquisition module, a signal processing module, a transmission module and a power supply module. A rotary optical filter (covering the range of 300nm to 750nm) is integrated in the optical detection module, and an appropriate optical filter is selected through circuit control to complete the filtering task of the fluorescent signal in a specific spectral range. The photomultiplier tube selects the appropriate sensitivity through the peripheral circuit, completes the photoelectric conversion, and changes the fluorescent signal into an electrical signal. The signal acquisition module and the signal processing module complete the signal acquisition, filtering and processing tasks, and feed back the results to the optical detection module to automatically control the detection parameters of the optical detection module; the power supply module has multiple outputs to provide the working voltage of the above modules .

①The rotary optical filter covers the wavelength range of 300-750nm, and the response wavelength range of the photomultiplier tube is consistent with the wavelength range of the optical filter, which is also 300-750nm;

②The sensitivity of the photomultiplier tube is adjustable within the range of 50A/lumen-0.0001A/lumen;

③The signal acquisition module adopts the resistance and low-frequency filtering method, and effectively collects the current signal of picoampere level through the signal acquisition and amplification circuit of the two-level cascade structure;

④ The power supply module adopts MAX 856 or MAX 743 chip, which provides voltage output of 5V and ±12V respectively, and has multiple outputs, which are respectively used for the working voltage of the signal processor and the operational amplifier.

The detection instrument and the detection method of the invention can effectively solve the traditional problem that the hand-held instrument is difficult to detect weak fluorescent signals. The detection steps of the detector are:

(1) The detected biological sample is placed in the sample pool in the optical detection module;

(2) Select a suitable filter through the control circuit;

(3) The photomultiplier tube collects the fluorescent signal of the biological sample, and converts the fluorescent signal into a current output signal;

(4) The signal acquisition module realizes the acquisition and amplification of the photomultiplier tube current signal;

(5) The signal processing module has a digital filtering function and a feedback function. It uses a single-chip microcomputer combined with an analog-to-digital conversion chip to complete the signal reading and processing process, and feeds back the result to the optical detection module through another digital-to-analog conversion chip to control the output voltage. , Selection of optical filter and adjustment of detection sensitivity and gain of photomultiplier tube;

(6) Finally, the control process and detection results of step (5) are displayed by the signal display and transmission module.

Description of drawings

Fig. 1 is the schematic diagram of the principle of the total number of bacteria detection device structure;

Figure 2 is a schematic diagram of the principle of the optical detection module;

Fig. 3 is the circuit diagram of signal acquisition module;

Figure 4 is a circuit diagram of the signal processing module.

Detailed ways

In the following, specific implementations in accordance with the present invention will be described by using the detection instrument and detection method proposed by the present invention, in conjunction with the accompanying drawings, for the detection requirements of trace amounts of adenosine triphosphate (ATP).

The detection instrument mainly includes an optical detection module 1 , a signal acquisition module 2 , a signal processing module 3 , a signal display and transmission module 4 and a power supply module 5 . The optical detection module 1 mainly includes two parts: an optical filter 8 and a photomultiplier tube 9, wherein the photomultiplier tube PMT is selected from the H6780 photomultiplier tube of Hamamatsu Corporation of Japan. The response range of the photomultiplier tube is between 300nm and 750nm, and the sensitivity is 50A/lumen. The optical detection module 1 is assembled in the sealed cavity 10 processed by metal aluminum material, effectively shielding the influence of external light and electromagnetic interference, and improving the detection sensitivity; during detection, biological samples are placed in the sample pool 6 in the optical detection module 1 Inside, select the appropriate filter 8 (~600nm) by controlling the motor 7 to rotate the wheel. A photomultiplier tube then collects the fluorescent signal from the biological sample and converts it into an electrical current output signal. The signal acquisition module 2 is used to realize the acquisition and amplification of the PMT output current signal. Since the fluorescent signal released by the low-concentration ATP reaction is extremely weak, the effective output of PMT is a low-frequency pA-nA level current signal. Therefore, the signal acquisition module 2 adopts a signal acquisition and amplification circuit based on a sampling resistor 11 and a low-frequency filter 12, and a two-stage cascaded structure, wherein the amplification factor of the first stage 11 is 1×10 ⁸ V/A, and the amplification factor of the second stage 12 100 times. The signal processing module 3 uses a single-chip microcomputer STC89C5213 combined with an analog-to-digital conversion chip MAX19715 to complete the signal reading and processing process, and a digital-to-analog conversion chip MAX53014 is used to output control voltage, complete the selection of optical filters and adjust the detection sensitivity and gain of the PMT module. The transmission module 4 adopts the liquid crystal display module YM12864J of Dalian Jiadisplay Electronics Co., Ltd., which is used to display the control process and test results. The power supply module 5 adopts MAX856 and MAX743 chips, which provide voltage outputs of 5V and ±12V respectively.

Claims (8)

1. A hand-held bioluminescence detector, characterized in that said detector comprises an optical detection module, a signal acquisition module, a signal processing module, a display and transmission module and a power supply module; the optical detection module integrates a rotary filter through the circuit control to select the appropriate filter to complete the task of filtering out the fluorescent signal in a specific spectral range; the photomultiplier tube selects the appropriate sensitivity through the peripheral circuit to complete the photoelectric conversion and convert the fluorescent signal into an electrical signal; signal acquisition The module and the signal processing module complete signal collection, filtering and processing, and feed back the results to the optical module to automatically control the detection parameters of the optical module; the power module has multiple outputs to provide the working voltage of the above modules. 2. by the described detector of claim 1, it is characterized in that described rotary optical filter covers 300-750nm wavelength range, and the response wavelength range of photomultiplier tube is consistent with optical filter wavelength range, also is 300-750nm wavelength range. 750nm. 3. The detector according to claim 2, characterized in that the sensitivity of the photomultiplier tube is adjustable within the range of 50A/lumen-0.0001A/lumen. 4. The detector according to claim 1, characterized in that the signal acquisition module adopts resistance and low-frequency filter mode, and through the signal acquisition and amplification circuit of the secondary cascaded structure, the current signal of picoampere level is effectively collected. 5. The detector according to claim 1, characterized in that the amplification factor of the first stage resistance is 1×10 ⁸ V/A, and the amplification factor of the second stage is 100 times. 6. by the described detector of claim 1, it is characterized in that described power supply module adopts MAX856 or MAX 743 chip, provides the voltage output of 5V and ± 12V respectively, has multi-channel output, is respectively used in signal processor and operation amplifier operating voltage. 7. use the detection method of the detector described in any one in claim 1-6, it is characterized in that concrete steps are: (1) The detected biological sample is placed in the sample pool in the optical detection module; (2) Select a suitable filter through the control circuit; (3) The photomultiplier tube collects the fluorescent signal of the biological sample, and converts the fluorescent signal into a current output signal; (4) The signal acquisition module realizes the acquisition and amplification of the photomultiplier tube current signal; (5) The signal processing module has a digital filtering function and a feedback function. It uses a single-chip microcomputer combined with an analog-to-digital conversion chip to complete the signal reading and processing process, and feeds back the result to the optical detection module through another digital-to-analog conversion chip to control the output voltage. , Selection of optical filter and adjustment of detection sensitivity and gain of photomultiplier tube; (6) Finally, the control process and detection results of step (5) are displayed by the signal display and transmission module. 8. by the described method of claim 7, when it is characterized in that detecting adenosine triphosphate, 1. select the photomultiplier tube to be the H6780 photomultiplier tube of Japan Binsong Company for use; 2. select the optical filter wavelength to be 600nm; It is STC89C52; the model of the digital-to-analog conversion chip used to output the control voltage is MAX530, and the model of the analog-to-digital conversion chip that completes the signal reading and processing process is MAX197.

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