| Enzyme-linked immunosorbent assay(ELISA)is a popular laboratory technique for the detection of biomarkers.This method has the advantages of high sensitivity and specificity.However,ELISA requires intensive human labor and time-consuming procedures,as well as trained operators and specialized testing rooms.In the case of limited resources,it is very important to simplify the miniaturization of programs and devices for ELISA-based nursing point detection(POCT).In this study,we propose an automated,low-cost portable POCT platform,which uses automatic pump valves to control the flow of reagents according to the requirements,so as to achieve automatic ELISA detection on the chip.Different from the photoresist or chemical etching method used in the laboratory to make the chip,this experiment uses the laser processing method to quickly process the polymethyl methacrylate plate,which reduces the processing cost and difficulty of the detection chip from the aspects of material and fabrication.At the same time,the chip channel is processed in the experiment,and the defect of the chip caused by laser processing is eliminated.after the chip channel processing,the flow of each channel is good and the flow is stable,which meets the demand of flow control for immune detection.In the experiment,the micro-pump valve is integrated into the detection chip,and the programmed flow of reagents in the chip is realized.In this method,different ELISA are controlled by microfluidic chip to enter the reaction chamber containing immunomagnetic beads to react.Based on the manipulation of permanent magnets,the magnetic fluid is separated and the magnetic beads are left in the reaction chamber to form an immunomagnetic bead-antigenantibody sandwich structure.Finally,the color signal produced by the enzyme catalytic substrate is converted into highly sensitive enzyme readings for quantitative biological analysis.Without additional equipment and complex operation,our automatic immunodetection chip method can carry out sensitive quantitative analysis of disease biomarkers within 2 hours.the automatic immunoassay method also shows high specificity,high precision and high accuracy.In addition,the ELISA detection method used in this study has a high versatility,so it can be applied to the detection of various protein biomarkers.This detection method not only has great application potential in the environment with limited resources,but also improves more choices for bedside diagnosis.In order to test the feasibility of the automatic detection chip,the chip was used to detect the inflammatory factor interleukin-6(IL-6).As a detection target,clinical detection of IL-6 is particularly important in the intensive care unit.A good bedside detection platform can provide a strong diagnostic basis for clinicians,which requires bedside detection to give fast and accurate detection results.In our country,bedside detection needs to develop a new bedside detection platform to successfully achieve automatic detection of IL-6 in this study.And the detection limit of 0.039ng/m L is the same as that of orifice plate ELISA detection method,which can meet the clinical needs. |
