Research On Portable Sensor Based On Fluorescence

According to medical reports,the incidence of premature babies in China is approximately5.6%,and its mortality rate reaches 12.7～20.8%.The body functions of premature babies are extremely fragile.It is easy to cause neonatal diseases such as hypothermia,abnormal respiratory system,etc.Therefore,it is necessary to put the premature babies in a stable environment incubator for monitoring.In view of this situation,a sensor that detects oxygen concentration and temperature in the incubator in real time is particularly important.In this paper,a fluorescent portable sensor is designed to solve the problem of simultaneous monitoring of oxygen and temperature.Traditionally,most sensors based on fluorescence light use fiber optic system,but this system has disadvantages such as bulky size,high R&D cost,and cumbersome monitoring,so the realization of dual-parameter monitoring still has a lot of room for development.The fluorescent light-emitting portable sensor of this paper can sense the changes of oxygen concentration and temperature by the variations of the fluorescence intensity of the dual sensing film.The specific research work is as follows:(1).The purpose of this paper is to prepare the dual-parameter fluorescence sensor for oxygen and temperature,analyze the types of fluorescence sensors;analyze the feasibility of the preparation and film formation of sensor materials;select appropriate fluorescent probes and matrix material according to the characteristics of the portable fluorescent sensor.;choose a suitable fixation method in accordance with the selected fluorescent probe,and systematically summarize the sensing mechanism of each parameter.(2).In this paper,a single excitation light source of 405 nm was used,Pt TFPP with an emission peak at 650 nm and Cd Se/Zn S with an emission peak at 525 nm are selected as the fluorescent probes for oxygen and temperature,and D4 polyurethane hydrogel is used as the sensing matrix.The dual-sensing membrane was prepared by the physical embedding method.Through fluorescence analysis,it is concluded that the dual sensing film has two nonoverlapping emission peak spectra,and can be well applied to the dual oxygen and temperature sensing system.The sensitivity of oxygen sensing is high,and the temperature sensing accuracy has a small error within the measured range.Its stability is strong.(3).The portable system in this paper can collect,process and display the fluorescence information of the dual sensor film.Firstly,the designed power management module can provide a stable voltage output,and the single excitation light source is controlled by the chip CN5611;secondly,the added optical path module can reduce the influence of ambient light on the excitation light source;then the color sensor chip TCS2300 is used as the core of the color detection module,this module can collect,process,and transmit the color change information of the dual sensor film;finally,the detected data information can display on the OLED module.After many experiments on this system,the conclusion is that the voltage output of the portable fluorescent sensor is not affected by the changes of oxygen concentration and temperature within the range of 15～60℃.And the system has good stability.(4).The verified dual sensor film is fixed on the dichroic mirror by coating.The oxygen concentration and temperature are changed using a constant temperature bath and an automatic gas distributor.Then the fluorescence signal of the dual sensor film is collected through a portable sensor system,processed and transmitted.The real-time test results of the experiment show that the relative accuracy of oxygen detection is-15.3～11.75%,the relative accuracy of temperature detection is-3.14～2.36%;the response time is 124 s.The fluorescence portable sensor can maintain good stability within one month.