RU70577U1 - TABLET MICROCOLORIMETER - Google Patents

Abstract

This utility model relates to the field of calorimetry and, in particular, to automated colorimeters designed to measure the degree of light absorption of a given wavelength in liquid samples, and can be used in biology, medicine, food industry and many other fields.

The technical task of the utility model is to simplify the design, reduce its dimensions and increase the speed of the device.

To solve this problem, in a tablet microcolorimeter containing light sources, light detectors, and a tablet with cells for samples of the test reagent, the light sources are program-controlled emitters with a given wavelength of light radiation, for example, LEDs.

In this case, the LEDs can have different wavelengths of light radiation.

As light receivers, a common photosensitive element, for example, a solar cell element, can be used.

Optimal is the supply of the tablet repeating its configuration liner made of opaque material.

The insert may be made of heat-conducting material and equipped with an electronic thermostat.

Description

This utility model relates to the field of calorimetry and, in particular, to automated colorimeters designed to measure the degree of light absorption of a given wavelength in liquid samples, and can be used in biology, medicine, food industry and many other fields.

Currently, most analytical methods for determining the concentration of any substances are based on measuring the optical characteristics of color solutions obtained in the course of a special reaction, individual for each type of study. Such devices are called photometers, spectrophotometers or colorimeters. Now such measurements are carried out in the so-called single immunological tablets (microplates). Measuring devices operating on this principle are called scanning or flatbed microcolorimeters, or readers.

Any modern analytical laboratory: chemical, biochemical, pharmacological, clinical; laboratories associated with environmental monitoring, various SES, Ministry of Emergencies, etc., must have one or more devices of this type.

Known measuring devices - microcolorimeters (readers) consist of a light source (incandescent or mercury lamp), a band-pass filter that cuts out only a given light radiation in a narrow (10-20 nm) region of the optical spectrum, a light focusing system and a collector (prism system, mirrors, optical fibers, etc.), dividing the light beam into 8 or 12 separate light beams directed to the wells of the tablet, into which the samples of the test reagent are dosed so that these beams pass through the studied liquid is only holes in one row (consisting of 8 or 12 holes) of a 96-well plate (or individual strips with holes - the so-called strips, for 8 or 12 holes each), and, passing through the sample, would focus on the corresponding (8 or 12) individual photodetectors (usually photodiodes).

Further, the analog signal from these photodetectors is digitized, and in the form of values of the optical density of the solution, is displayed on the appropriate storage medium (electronic display of the device, printer, computer monitor screen, etc.).

The main most expensive and bulky part of such a reader is a mechanism that moves the tablet in two mutually perpendicular directions relative to a ray of light passing through each well of the tablet in series; in this case, each well with the test solution is sequentially installed exactly under a beam of light with a given wavelength, which, passing through the color solution in the well, attenuates its intensity and enters one or more light detectors, by means of which the value of this attenuation is recorded, recounting it later in the concentration of the test substance.

This mechanism performs a reciprocating movement of a 96-well plate in such a way that the tablet moves step by step (in 8 or 12 steps) relative to the line of optocouplers - 8 or 12 light rays from the light source and their corresponding 8 or 12 light receivers, which makes it possible to measure the optical density of all samples in all 96 wells of the plate.

These devices are quite versatile and allow you to perform various analyzes using light rays of different spectral regions (e.g., 400 nm, 450 nm, 560 nm, 600 nm.). The cost of such devices ranges from five to several tens of thousands of dollars.

Their high price mainly consists of the cost of two main components required for all devices of this type:

- a unit of complex and precision mechanics (guides, servos, position sensors, etc., requiring precision high-tech equipment for their production);

- a node that is also extremely expensive - optics (illuminators with halogen or mercury lamps, mirrors, lenses, optical fibers, precision light filters, etc.).

Closest to this utility model is the THERMOmax microplate reader colorimeter, USA, containing a light source - a halogen incandescent lamp, an automatic switchboard consisting of 4 optical filters and an optical system that focuses light of a given wavelength at the input end of a thin fiber. This light passing through the second light guide then goes to the light switch, in which the output end of this light guide is sequentially combined with the mechanical assembly of the carousel type with the input ends of 96 other light guides, the output ends of which are installed above and in the center above all 96 immunological plate wells. Below, under each of these optical fibers there is an individual photodetector for each well of the plate - a photodiode (i.e. formed

96 optocouplers “optical fiber-photodiode”). Thus, a ray of light passes sequentially through each of the wells of the tablet, and the value of the optical density of the solution in each of these holes is converted into an electric signal through 96 light detectors, then it is digitized and, as a result of the measurement, displayed on a monitor (or printer) of a personal computer connected to the device. A tablet with the help of a special mechanical unit can travel outside of the measuring chamber or move inside it, so that on top of the tablet above each well is the end of one of 96 optical fibers, and a photodiode is installed under the bottom of each well (there are also 96 of them)

The disadvantage of the prototype is its bulkiness, the complexity of the entire structure and, in particular, the switch for switching light filters and the switch for switching light beams, as well as the presence in the structure of complex precision and at the same time insufficiently reliable mechanical components. In addition, the device has a low speed, since the sequential calculation of channels is carried out due to inertial mechanical movement (96 steps per measurement cycle) of the switch parts.

The technical task of the utility model is to simplify the design, reduce its dimensions and increase the speed of the device.

This technical problem is solved by using in the proposed tablet microcolorimeter containing light sources, light detectors, and a tablet with cells for samples of the test reagent, as light sources of program-controlled emitters with a given wavelength of light radiation, for example, LEDs.

In this case, the LEDs can have a different wavelength of light radiation, and a common photosensitive element, for example, a solar cell element, can be used as light receivers.

The microcolorimeter tablet may be equipped with a repeating insert made of an opaque material. In this case, the insert can be made of heat-conducting material and equipped with an electronic thermostat.

The drawings presented schematically depict the proposed device:

figure 1 - tablet microcolorimeter with a common photosensitive element,

figure 2 - site with 96 light receivers.

The proposed device contains light sources, which are mounted on a board 1 96 miniature LEDs 2, emitting in a narrow and precisely defined range of wavelengths; light receivers, which are a common photosensitive element 3 in the form of a solar cell element, as shown in Fig. 1 or - 96 photodiodes 4 mounted on a board 5, as shown in Fig. 2.

Between the light sources and the light receivers there is a plate 6 with 96 cells 7 for samples of the test reagent. The tablet is equipped with a repeating configuration of the liner 8, made of opaque material. The insert 8 can be connected to an electronic thermostat 9.

The device is equipped with a current pulse modulator 10, an electronic switch 11 and is connected to a personal computer 12.

The device operates as follows. A tablet 6, in all or part of the cells 7 of which samples are placed whose optical density must be measured, is placed in the device. The narrow beam of light formed by the LEDs 2, which briefly arises due to the sequential supply of 10 current pulses modulated in the modulator 10 to each of the 96 LEDs, is sequentially incident on the samples. Further, passing through the test fluid sample, the light attenuated due to absorption in the fluid enters one common for all cells 7 of the tablet 6, the photosensitive element 3 in the form of a solar cell element (figure 1) or 96 light receivers 4 (figure 2), individual for each of the 96 cells of the tablet, for example, photodiodes. The electronic switch 11 generates electrical signals for controlling the light and / or photodiodes, and the electric signal from the light receiver 3 or light receivers 4 is digitized and fed to a personal computer 12, the program of which automatically performs all the manipulations necessary for the operation of this device.

To test the optical properties of samples using different wavelengths of light radiation, LEDs 2 with different wavelengths of maximum radiation can be used.

At each moment in time, only one LED 2 shines during the measurement process, and, nevertheless, not all light from it passes exclusively through the measured sample. If the light receiver is common to all cells of the tablet, then part of the light through the transparent walls of neighboring cells can also fall on the light receiver. This distorts the measurement results, reducing their accuracy. You can increase the accuracy of measurements using

tablets or strips made of thin-walled material (for example, the company "COSTAR"). This design of the tablet allows you to equip it with a special liner 8, repeating its configuration and made of opaque material. At the same time, each cell 7 of tablet 6 is surrounded by opaque material on the sides, which practically negates the possibility of flare through neighboring cells.

For some types of analysis or testing, maintaining the temperature of the test sample at a given level during measurement is required. To do this, as, for example, in the prototype, thermostat the air in the entire volume of the measuring chamber, while also circulating it with a special fan, which complicates the design of the entire device and makes the temperature control process inertial. To solve this problem, the liner 8 of the proposed device is made of heat-conducting material, for example, copper or brass, and connected to the thermostat 9.

The advantages of the proposed device are as follows:

- sharply increases the processing speed of all samples placed in the tablet;

- dramatically increases the reliability of the entire device;

- the measurement accuracy increases, since the unstable glow of the incandescent lamp, and even more so, the mercury lamp is replaced by an extremely reliable and very stable in time LED light;

- the cost of such a device is reduced tenfold.

Claims (5)

1. A tablet microcolorimeter containing light sources, light detectors, and a tablet with cells for samples of the test reagent, characterized in that the light sources are program-controlled emitters with a given wavelength of light radiation, for example LEDs. 2. The microcolorimeter according to claim 1, characterized in that the LEDs have a different wavelength of light radiation. 3. The microcolorimeter according to claim 1, characterized in that as a photodetector use a common photosensitive element, for example, a solar cell element. 4. The microcolorimeter according to claim 1, characterized in that the tablet is equipped with a repeating configuration of an insert made of an opaque material. 5. The microcolorimeter according to claim 4, characterized in that the liner is made of heat-conducting material and is equipped with an electronic thermostat.