CN1295494C

CN1295494C - Integrated minisize optical analyser

Info

Publication number: CN1295494C
Application number: CNB2004100134182A
Authority: CN
Inventors: 陆晓华; 杨海; 王琳玲
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2004-07-04
Filing date: 2004-07-04
Publication date: 2007-01-17
Anticipated expiration: 2024-07-04
Also published as: CN1595105A

Abstract

The present invention discloses an integrated miniature optical analyzer. The integrated miniature optical analyzer comprises a light path part, a monolithic computer, an auxiliary circuit part and an input-output part, wherein the monolithic computer and the auxiliary circuit part are used for calculation and control; the input-output part is used for inputting and outputting information. The integrated miniature optical analyzer is characterized in that the light path part comprises a light source voltage stabilizing control circuit, a first monochromatic light source assembly, a second monochromatic light source assembly, sample tanks, an optical splitter, photoelectric detectors, a photoelectric sensor array and a signal modulating circuit; the first monochromatic light source assembly, the sample tank and the photoelectric detector are successively positioned on a first light path, the second monochromatic light source assembly, a sample tank, the optical splitter and a photoelectric detector are successively positioned on a second light path, and the first light path and the second light path have an included angle of 90 degrees. The present invention integrates a plurality of optical detection techniques, greatly reduces the size and the power consumption of analyzers, realizes the miniaturization of instruments, and can be used for simultaneous in-situ rapid determination of multiple components in environmental samples, food samples and other complicated samples.

Description

Integrated miniature optical analyzer

Technical Field

The invention belongs to an optical analysis and detection technology, and particularly relates to an integrated micro optical analyzer.

Technical Field

Environmental and food safety issues are of high concern to countries and the masses due to the great harm to the health of the masses caused by environmental pollution, abuse of pesticides, growth hormones and food additives. There are many test items for environmental analysis and food analysis, and their measurement principles are different, such as optical analysis (absorbance, fluorescence, luminescence, etc.), chromatography, etc., among which optical analysis is the most widely used analysis method due to its advantages such as simple instrument and easy operation. Various optical analysis methods have been widely used in food and environmental analysis. The development of miniaturized portable intelligent analysis instruments has also been greatly advanced in recent years.

However, the spectrophotometer, the fluorescence photometer, the luminescence analyzer and other instruments used in the laboratory at present are difficult to meet the requirements of field monitoring and supervision occasions such as the field, the trade market, the supermarket and the like on miniaturized, portable, rapid, simple and convenient analytical instruments for simultaneously measuring multiple components due to large volume, inconvenience in carrying and requirement of mains supply power supply. Moreover, instruments such as a spectrophotometer, a fluorescence photometer, a luminescence analyzer and the like are based on a single optical analysis principle, and cannot realize multi-component rapid determination based on multiple optical analysis measurement principles or acquisition of multiple optical measurement information of the same sample. And thus have many limitations in applications for rapid analysis of complex samples in field environments, food products, etc. For example, when measuring the chromaticity and COD in an environmental sample by absorptiometry, the turbidity in a water sample interferes, blank correction is often not effective in these cases, and sample pretreatment also affects the measurement result. Therefore, the water quality indexes such as chromaticity, COD and the like of the high-turbidity sample are difficult to accurately measure by the current single-function optical analyzer. The structure principles of instruments such as a spectrophotometer, a fluorescence photometer, a luminescence analyzer and the like have similarities, and the measuring methods also have advantages and disadvantages respectively. From the aspect of analysis application, the miniaturized instrument integrating various optical analysis principles can use different measurement principles to acquire qualitative and quantitative information of more sample components from complex samples and realize on-site rapid determination of various measured components. The integrated micro optical analyzer with the function of the optical analysis laboratory has practical significance in the analysis of complex samples in the field rapid analysis occasions of environment and food supervision.

At present, a miniaturized and portable spectrophotometer using an LED as a light source and a photodiode as a detector is a widely-used commercial instrument (such as HACH in the United states and HANNA in Italy), the instrument has dual purposes of alternating current and direct current, and is matched with a specific chemical reagent bag to be used, so that dozens of indexes can be conveniently measured, and the spectrophotometer is favored in the market of China in recent years. However, this instrument can only realize a single absorptiometry measurement function, and cannot realize fluorescence and luminescence analysis functions. Optical analyzers for various shapes and colors, such as fluorescence analyzers, luminescence analyzers, and scattering photometers, are also available on the market, but all have a single measurement function.

So far, no report of such a micro optical analyzer integrating a plurality of optical measurement technologies such as absorption luminosity, scattering luminosity, fluorescence luminosity and luminescence analysis has been found at home and abroad.

Disclosure of Invention

The invention aims to overcome the defects of the existing single-measurement-function instrument and provide an integrated micro optical analyzer which can simultaneously measure various optical indexes such as absorbance value, scattered light intensity, fluorescence intensity, luminous intensity and the like.

The invention provides an integrated micro optical analyzer, which comprises a light path part, a singlechip, an auxiliary circuit part and an input/output part, wherein the singlechip and the auxiliary circuit part are used for calculation and control, and the input/output part is used for input and output of information, and is characterized in that: the light path part comprises a light source voltage stabilization control circuit, a first monochromatic light source group, a second monochromatic light source group, a sample cell, a light splitter, a photoelectric detector, a photoelectric sensor array and a signal conditioning circuit; the first monochromatic light source group, the sample cell and the photoelectric detector are sequentially positioned on a first light path, the second monochromatic light source group, the sample cell, the light splitter and the photoelectric detector are sequentially positioned on a second light path, and the first light path and the second light path form a certain included angle; the light source voltage stabilization control circuit provides working voltage for the monochromatic light source according to signals provided by the singlechip and the auxiliary circuit part and controls the light source to be switched on and off; after a monochromatic light source group or a monochromatic light beam generating monochromatic light passes through a sample to be detected in a sample cell, a part of generated light signals directly irradiate a photoelectric detector, the total light intensity value is measured by the photoelectric detector and sent to a signal conditioning circuit, a part of the generated light signals irradiate a photoelectric sensor array through a light splitter, the light intensity value of each wavelength band is measured and sent to the signal conditioning circuit, the signal conditioning circuit shapes and amplifies each light intensity value, the light intensity values are output to a single chip microcomputer and an auxiliary circuit part for processing, and the result is sent to an input and output part; the first monochromatic light source group is assembled with a photoelectric detector, or the second monochromatic light source group is assembled with a light splitter and a photoelectric sensor array and used for absorption photometric analysis; the first monochromatic light source group is assembled with a photoelectric detector, or the second monochromatic light source group is assembled with a light splitter and a photoelectric sensor array and used for scattering photometric analysis; the first monochromatic light source group is assembled with the optical splitter and the photoelectric sensor array and used for fluorescence analysis; the photodetector, or beam splitter, is assembled with a photosensor array for luminescence analysis.

The invention provides a highly integrated micro optical analyzer capable of simultaneously measuring various optical indexes such as absorbance value, scattered light intensity, fluorescence intensity, luminous intensity and the like aiming at the current situation of an optical analyzer. Through special light path design, two sets of light sources and detectors can be combined as required, and functions of various optical analysis instruments such as a spectrophotometer, a fluorescence analyzer, a luminescence analyzer and a scattered light intensity meter are integrated on one instrument. The instrument discards a traditional heat light source and a photomultiplier detector which are bulky, and replaces a semiconductor light source group with small volume and low power consumption and a highly integrated micro detector, so that various optical detection technologies can be integrated in one instrument, the volume and the power consumption of the instrument are greatly reduced, and the miniaturization of the instrument is realized. The instrument is internally provided with a high-performance singlechip system, and can meet the requirements of high-speed sampling and complex numerical calculation. By the cooperative measurement of various optical indexes and the comprehensive analysis and processing of data, the simultaneous on-site rapid determination of various components in complex samples such as environment, food and the like can be realized. At present, similar instruments are not reported at home and abroad.

Drawings

FIG. 1 is a schematic block diagram of the instrument hardware;

FIG. 2 is a software flow diagram of the measurement portion of the instrument.

FIG. 3 is a schematic diagram of an optical bench of the instrument;

Detailed Description

The instrument mainly comprises three parts: an optical path part 1, a singlechip and auxiliary circuit part 2 and an input and output part 3. The light path part 1 mainly comprises a light source voltage stabilization control circuit 4, a first monochromatic light source group 5, a second monochromatic light source group 6, a sample cell 7, a light splitter 8, a photoelectric detector 9, a photoelectric sensor array 10 and a signal conditioning circuit 11. The single chip microcomputer and auxiliary circuit part 2 comprises a single chip microcomputer 12, a multi-way selection switch 13, a system monitoring circuit 14, a data storage circuit 15 and the like, and the input and output part 3 comprises a display device 16, an input device 17 and a communication circuit 18.

The light source voltage stabilization control circuit 4 provides a constant working voltage for the monochromatic light source and controls the on-off of the light source; the first monochromatic light source group 5 and the second monochromatic light source group 6 are composed of a series of semiconductor monochromatic light sources with different wavelengths, and the semiconductor monochromatic light sources with different wavelengths (from ultraviolet region to near infrared region) can be selected to be combined according to the requirements of the analysis method of the sample to be detected. The two monochromatic light sources are vertically arranged at 90 degrees (see fig. 3); the sample cell 7 is used for placing a sample to be tested; the light splitter 8 is used for splitting the composite light into monochromatic light with different wavelengths; the photodetector 9 is used for converting the total light intensity signal into an electric signal; the photoelectric sensor array 10 is used for respectively detecting light intensity values with different wavelengths and converting the light intensity values into electric signals; the signal conditioning circuit 11 can amplify and shape the output electric signal; the singlechip 12 is the operation and control core of the whole instrument; the multi-way selection switch 13 can select a proper light source and detector according to the instruction of the singlechip 12; the system monitoring circuit 14 can monitor the running state of the system at any time to prevent the program from flying away; a data storage circuit 15 for storing data in the nonvolatile memory EEPROM; the display device 16 and the input device 17 provide a good human-machine interface; the communication circuit 18 is used for data exchange with a PC or a serial printer.

After the user selects the optical index to be measured according to the requirement, the single chip microcomputer 12 can automatically select a proper light source to be combined with the detector. Under the control of the singlechip system, the monochromatic light source with the corresponding wavelength in the monochromatic light source group 5 or the monochromatic light source group 6 is lightened by the multi-path selection switch 13 and the light source voltage stabilization control circuit 4 to generate monochromatic light. After passing through a sample cell 7 filled with a sample to be detected, the monochromatic light beam is subjected to the actions of sample absorption, scattering and the like, a part of generated light signals are directly irradiated on a photoelectric detector 9, and a part of generated light signals are irradiated on a photoelectric sensor array 10 after passing through a light splitter 8. When monochromatic light is irradiated onto a sample, scattered light is generated in other directions in addition to transmitted light. Some samples also produce fluorescence and chemiluminescence, among other things. The types of optical signals detected by the detectors at different positions are different. How to collect and process these optical signals is a relatively complex problem and is not in the scope of the patent discussion. The photodetector 9 can directly measure the total light intensity value, and the beam splitter 8 and the photosensor array 10 can respectively measure the light intensity values of different wavelength bands. The light intensity values are shaped and amplified by the signal conditioning circuit and then can be input into the singlechip through the multi-way selection switch 15. The single chip can selectively collect signals according to the test requirements to obtain corresponding measurement results such as absorbance values, scattering light intensity values, fluorescence values, luminous intensity values and the like, and can further comprehensively process the measurement results according to different algorithms. All measurement data is stored in a nonvolatile data memory through a data storage circuit 15 and can be inquired and summarized by a user. The display device 16 and the input device 17 are main input and output devices and can provide a good human-computer interface. The communication circuit 18 can also realize the data exchange function with a PC, and an external printer can also directly print the measurement result. The system monitoring circuit 14 constantly monitors whether the working state of the system is normal or not, and the stability and reliability of the instrument are ensured.

TABLE 1 combination of several optical analysis methods

Analytical method	Light source	Detector
Analytical method	Light source	Detector	Absorptiometry analysis scattering photometry analysis fluorescence analysis luminescence analysis	Monochromatic light source group (A)5 monochromatic light source group (B)6 monochromatic light source group (A)5-	Photodetector 9 spectrometer 8+ photosensor array 10 photodetector 9 spectrometer 8+ photosensor array 10

The program of the integrated micro optical analyzer can be written in a high-level language C. The whole software can be divided into four modules: parameter setting, sample measurement, data processing and system setting. The parameter setting module is mainly used for completing the setting related to the measurement, and a user can designate the measurement wavelength, select a detector group, designate the measurement mode (absorption luminosity, scattering luminosity, fluorescence, luminescence analysis) and the like according to the requirement; the sample measurement module is the core of the entire software. Measuring a sample according to a measurement setting value of a user, and completing functions of monochromatic light selection, detector selection, sample measurement control, data acquisition, calculation and display of a measurement result and the like; the data processing module is responsible for completing tasks such as storage, query, printing of measurement results, data exchange with a PC and the like; the system setting module comprises auxiliary functions of system time setting, display screen contrast setting, input equipment correction and the like.

All the above parts can be realized by adopting the prior art.

The present invention will be further described with reference to an example.

A plurality of narrow-band light-emitting diodes (LEDs) with specific wavelengths can be selected as monochromatic light sources to construct a monochromatic light source group (A)5 and a monochromatic light source group (A)6, so that a thermal light source and a light source monochromator system of the existing laboratory spectrophotometer can be replaced. The currently available commercial monochromatic LEDs have wide wavelength ranges, various wavelengths such as 270, 420, 460, 520, 560, 590, 640, 700 and 840nm can be selected, ultraviolet, visible light and near infrared light regions are basically covered, and the requirements of different measurements can be met;

the highly integrated micro semiconductor photodetector such as TSL235 of TASO corporation, OPT101 of TI corporation, etc. has small volume, low power consumption, wide spectral response range, and stable and reliable performance, and is an ideal choice for the photodetector 9. CCD array detector products such as TCD1208 from Toshiba, TCD1500, and IL-P3-2048 from DALSA are well-established and may be used as photosensor array 10. The beam splitter 8 may be a grating or a prism.

By selecting photoelectric devices, a highly integrated optical analysis platform integrating absorption luminosity, scattering luminosity, fluorescence, luminescence analysis and other optical measurement principles can be constructed.

As a signal processing and control core, the single chip microcomputer 12 may select an enhanced 8-bit or 16-bit single chip microcomputer product, such as C8051F of Cygnal, MSP430 of TI, and the like; the multi-way switch 13 can select CD 4051; the system monitoring circuit 14 can select MAX813 chips to realize watchdog, automatic reset, voltage monitoring and other monitoring functions; the data storage circuit 15 may be implemented using a 24LC series EEPROM product.

The display device 16 can be a large-screen Liquid Crystal Display (LCD), and the touch screen and the keyboard form the input device 17. The RS-232 serial interface chip (such as MAX3233) can be used for constructing the communication circuit 18 to realize the functions of PC communication, serial printing and the like

The light source, the detector, the chip and the main devices have small volume and light weight, can normally work under 5V direct current voltage, and can be directly powered by a battery. These make possible a miniaturized design of the instrument.

The integrated micro optical analyzer can be written by adopting a Keil C singlechip language popular in foreign countries, and comprises four modules of parameter setting, sample measurement, data processing and system setting. The modular programming language has the characteristics of the universal C language and the capability of directly operating the hardware of the singlechip, and has the basic characteristics that: the method has the advantages of high running speed, high compiling efficiency, good portability and abundant library functions and floating-point operation capability of various complex operations. A software flow diagram of the sample measurement module is shown in fig. 2.

Table 2 lists the main functional comparisons of several conventional large photometric analyzers and the present instrument.

TABLE 2 comparison of several optical analysis instruments

Instrument for measuring the position of a moving object	Function(s)
Instrument for measuring the position of a moving object	Function(s)	Spectrophotometer and infrared spectrophotometer and fluorescence spectrophotometer	Ultraviolet-visible absorption photometry near-infrared, infrared photometry scattering photometry fluorescence photometry, luminescence analysis ultraviolet,Visible light and near infrared absorption photometric analysis scattering photometric analysis, fluorescence photometric analysis, and luminescence analysis

Claims

1. An integrated micro-optical analyzer, comprising an optical path part, a single-chip microcomputer and an auxiliary circuit part and an input-output part, the single-chip microcomputer and the auxiliary circuit part are used for calculation and control, and the input-output part is used for input and output of information, and is characterized in that: The optical path part (1) includes a light source voltage stabilization control circuit (4), a first monochromatic light source group (5) and a second monochromatic light source group (6), a sample cell (7), a beam splitter (8), a photoelectric The detector (9), the photoelectric sensor array (10) and the signal conditioning circuit (11); the first monochromatic light source group (5), the sample cell (7) and the photodetector (9) are sequentially located on the first optical path, and the second The two monochromatic light source groups (6), the sample cell (7), the beam splitter (8) and the photodetector (9) are located on the second optical path in turn, and the first optical path and the second optical path form an angle of 90 degrees; the light source is stabilized The control circuit (4) provides the operating voltage for the monochromatic light source according to the signal provided by the single-chip microcomputer and the auxiliary circuit part, and controls the switch of the light source; the monochromatic light beam generated by the monochromatic light source group (5 or 6) passes through the sample cell After the sample to be tested in (7), a part of the generated optical signal is directly irradiated on the photoelectric detector (9), the total light intensity value is measured by it and sent to the signal conditioning circuit (11), and a part passes through the optical splitter (8) Irradiate on the photoelectric sensor array (10), measure the light intensity value of each wavelength band and send it to the signal conditioning circuit (11), the signal conditioning circuit (11) will shape and amplify each light intensity value, and output it to the single chip microcomputer and auxiliary circuit part be processed, and the result is sent to the input and output part; among them,

The first monochromatic light source group (5) is combined with a photodetector (9), or the second monochromatic light source group (6) is combined with a beam splitter (8) and a photoelectric sensor array (10) for absorbance photometric analysis ;

The first monochromatic light source group (5) is combined with a photodetector (9), or the second monochromatic light source group (6) is combined with a beam splitter (8) and a photoelectric sensor array (10) for scattered photometric analysis ;

The first monochromatic light source group (5) is combined with a beam splitter (8) and a photoelectric sensor array (10) for fluorescence analysis;

A photodetector (9), or a beam splitter (8) is combined with a photosensor array (10) for luminescence analysis.