Our project is very complicated. To obtain the final fluorescence signal, the sample needs to be treated with muti-step process. The fluorescence signal requires special equipment to be accurately read, otherwise the correct result will not be obtained due to the strong interference of the background light. Therefore, we divided the device into three parts: a detector for fluorescent signals reading, a microfluidic chip for samples processing, and a Cas13 protein chip for conversion of nucleic acid signals into fluorescent signals.
It has the following functions:
1.The biggest advantage of our detector is that it can rotate the servomotor to change the wavelength of the filter on the optical path, so as to achieve the purpose of detecting different fluoresceins in the same sample. It can measure the fluorescence intensity of four kinds of fluorescein in one cycle, and can give the change curve of four kinds of fluorescein concentration with respect to time at the same time.
2.In order to reduce the photobleaching effect of fluorescein, control the illumination time of each detection to 1s.
3.The light source LED is connected to a 3.3v voltage regulator tube, which can keep the brightness of the LED stable and make the data reliable.
4.This device can store the measured values obtained by four different channels into the SD card, which is convenient for data processing on the computer.
5.This device has a display that can reflect real-time data, which is convenient for professionals to debug this device.
For more details, please click>>DETECTOR<<
In order to facilitate the user's operation, we designed a microfluidic chip to automate the reaction. At this time, the user only needs to put the sample probe into the sample chamber of the chip, cover the plug of the sample chamber, and put the chip in the microfluidic control device, and the subsequent operations are controlled by the microcomputer.
1.The sample can be heated and cooled at the same time.
2.The temperature can be controlled to 37-40℃, and the sample can be amplified by RPA. And before the amplification, the sample that was pyrolyzed is cooled in advance to prevent the protein from lyophilization and denaturation.
For more details, please click >> Microfluidic Chip<<
The protein on the Cas13 protein chip is the core biological component of our project-the four brothers of the Cas13 family. They respectively identify the four virus diseases in the sample and cut the corresponding four probes. Then we can judge the positive status of the virus based on the cutting conditions of the probes.
1. The whole board is very small and portable.
2. Simple structure, low hardware cost.
For more details, please click >> Detection Chip<<
We designed four generations of devices in total, and finally chose the fourth generation under the advice of the company. Many difficulties came up during the production of this device, which were documented in another document.
For more details, please click>> History<<
We also wrote a related document to briefly explain the making process of this device and to provide ideas for subsequent teams to design and build the device.
For more details, please click >> Contribution<<