‘Light and Enzyme‘ Synergy of Biochemical Analyzers

In the detection system ofbiochemical analyzers,the specific catalysis of enzymes and the precise signal conversion of light form a tight synergy,which constitutes the core foundation of accurate detection in fields such as clinical diagnosis and environmental monitoring.This collaboration is not simply a superposition,but a closed loop of"enzyme amplification signal light capture signal data quantification analysis"to achieve high-sensitivity detection of trace target substances. Its inherent mechanism and technical implementation logic are worth further disassembly.

　　1、Collaborative essence:enzyme signal amplification and light signal reading

The synergistic core of enzymes and light lies in their complementary functions:enzymes solve the problem of"specific recognition and signal amplification",while light plays the role of"signal conversion and quantitative reading",jointly breaking through the technical bottleneck of micro detection.

The core function of enzymes is reflected in specific catalysis and signal amplification. The concentration of test substances(such as antigens and metabolites)in biological samples is often extremely low,making direct detection extremely difficult. Through enzyme labeling technology,enzymes are bound to specific recognition molecules(such as antibodies). When the recognition molecule binds to the analyte,the enzyme can catalyze chemical changes such as color and fluorescence of the substrate-one enzyme molecule can catalyze the conversion of thousands of substrate molecules in a short period of time,achieving exponential amplification of the signal. For example,when detecting blood glucose,glucose oxidase can specifically catalyze the generation of hydrogen peroxide from glucose. Each molecule of enzyme can catalyze hundreds of substrate reactions,significantly enhancing weak blood glucose signals.

The core function of light is to accurately capture chemical signals and convert them into electrical signals. The chemical changes produced by enzyme catalysis,such as color depth and fluorescence intensity,need to be quantified through an optical system. The optical system of abiochemical analyzerusually consists of a light source,a monochromator,and a detector:the light source emits light of a specific wavelength(such as visible light LED,laser)to irradiate the reaction system,the monochromator filters out characteristic wavelength light to avoid interference,and the detector(such as photomultiplier tube,optical sensor)measures the absorption,reflection,or emission intensity of light,converting chemical signals into computable electrical signals. This conversion has a high linear correlation,such as the darker the color,the greater the light absorption intensity,and the corresponding higher the concentration of the tested substance.

　　2、Technical Implementation:From Basic Mechanisms to Advanced Design

The synergy between light and enzymes requires precise technological design and implementation,including both traditional single signal detection and new multi-mode synergy systems.

（1）Traditional collaborative mode:enzymatic colorimetric and absorbance detection

The most classic collaborative case is colorimetric detection in enzyme-linked immunosorbent assay(ELISA). Take the detection of hepatitis B surface antigen as an example:first,let the antigen in the sample combine with the antibody on the solid carrier,then add the enzyme labeled antibody to form a complex,and finally add the substrate(such as TMB). At this point,horseradish peroxidase catalyzes the oxidation of the substrate to a blue product. The analyzer measures the absorbance using light with a wavelength of 630nm,and the antigen concentration can be calculated by comparing the absorbance value with the standard curve. In this mode,the specificity of the enzyme ensures no cross interference in the detection,and the quantitation of light ensures the accuracy of the results.

（2）Advanced collaborative mode:multi signal linkage and photo controlled catalysis

With the development of technology,collaborative systems are upgrading towards"dual signal calibration"and"photo controlled catalysis". In the alkaline phosphatase(ALP)detection platform developed by the Fuzhou University team,the three component covalent organic frameworks(COFs)possess both oxidase and ascorbate oxidase activities:under visible light irradiation,COFs catalyze the oxidation and coloration of substrate TMB(colorimetric signal),while the generated substance reacts with another substrate to produce fluorescence(fluorescent signal). In this system,light serves as both a catalytic activation condition and a reading medium for dual signals. The two signals are mutually calibrated,reducing detection errors to below±1%and significantly improving detection accuracy in complex samples.

Another innovative direction is the application of photoactivated nanoenzymes. Nanomaterials such as gold nanorods and polymer dots exhibit enzymatic activity under specific light irradiation,and the catalysis immediately terminates when the light source is turned off-this light controlled characteristic can accurately regulate the start and stop of enzymatic reactions. Combined with the surface plasmon resonance(SPR)effect of alloy nanorods,it can sensitively capture changes in enzyme activity through the displacement of light absorption peaks,and the detection limit can be as low as 0.1 ppm.

　　3、Collaborative value:driving performance breakthroughs in detection technology

The synergy between light and enzymes directly determines the core performance indicators ofbiochemical analyzers,demonstrating irreplaceable value in clinical diagnosis and scientific research fields.

In clinical diagnosis,the collaborative system achieves"early detection and accurate judgment". Taking the detection of cardiac troponin as an example,by combining the signal amplification of horseradish peroxidase with fluorescence spectrophotometry,the detection limit can reach 0.01ng/mL,which can be detected within 1-2 hours after myocardial infarction,4-6 hours earlier than traditional methods,saving time for rescue. At the same time,the high specificity wavelength selection of light can eliminate interference from substances such as hemoglobin in the blood,improving the detection accuracy to over 99%.

In technological upgrading,collaborative innovation promotes the evolution of detection towards"multi parameter,low interference". Traditional single signal detection is susceptible to environmental influences,while dual-mode detection based on light and enzymes(such as colorimetric fluorescence combination)can resist interference substances in complex matrices(such as serum and soil leachate)through self calibration of two optical signals,reducing the repeatability error of enzyme activity detection in environmental monitoring from±5%to below±2%. In addition,the application of photo controlled enzyme catalysis technology reduces reagent consumption and lowers the cost of single detection by more than 30%.

　　4、Collaboration key:system matching and performance optimization

To achieve efficient synergy between light and enzymes,attention should be paid to three core matching points:firstly,optical adaptation between enzymes and substrates. For example,when selecting a chromogenic substrate with a characteristic absorption peak at 450nm,a corresponding wavelength light source and detector should be used; The second is the balance between light intensity and enzyme activity. Excessive light may cause enzyme denaturation,while insufficient light may affect signal intensity. The optimal light intensity range needs to be determined through preliminary experiments; The third is precise control of reaction time. Enzyme catalysis needs to reach reaction equilibrium,while light detection needs to avoid substrate depletion. Usually,the timing coordination of"enzyme reaction light detection"is achieved through program settings.