We designed an instrument to sense glucose concentrations in real time. When the blood glucose concentration exceeds a certain value, the switch can be triggered to activate the blue light. We have performed real-time detection of its concentration in glucose solution.
In our design, the role of the hardware instrument is to control whether the blue light is irradiated or not based on the change in glucose concentration. From this, we logically came up with three components together: the Glucose Detection Device, the Monitor, and the Instrument Emitting Blue Light.
To achieve our ideal design above, we learned about the biochemical principle of the glucose concentration test strip method. Ideally, glucose reacts with glucose oxidase on the test strip. And during the reaction, glucose is oxidized to gluconic acid, while hydrogen peroxide is generated. The produced hydrogen peroxide reacts with an indicator on the test strip, resulting in a color change, and the extent of the color change is proportional to the glucose concentration, which can be determined by comparing it to a standard color chart or using a measuring instrument. These are the principles that we conduct the detecting system of our hardware.
To visualize the test results, we utilize a display screen that showcases the glucose concentration. By comparing the measured concentration with predefined threshold values, our instrument will emit blue light if the concentration exceeds the threshold, and vice versa.
In the future, we plan to anticipate the use of the device in mice for minimally invasive blood glucose concentration monitoring and the wristband in humans to monitor changes in blood glucose concentrations in real time to achieve our desired results.
A glucose sensor with a soft needle will be implanted under the skin, and glucose oxidase will be used to continuously measure the consumption of liquid oxygen or the production of hydroxide ions in the subcutaneous tissue every 10 seconds, and then convert it into a glucose value. The glucose value will be sent to the main control module through Bluetooth for data processing, and the blue light device will be switched and controlled according to the received glucose value and glucose threshold. When the glucose value reaches the threshold, the blue level will be opened, and vice versa.
Fig 1. The glucose sensor
Fig 2. The master control module
After the near-infrared light is irradiated into the human body, the near-infrared light will be transmitted
and diffused in the human tissues, and the sensor will be used to receive the spectrum passing through the human
body, and these spectra contain information about the concentration of glucose in the human body.
Based on near-infrared spectroscopy and stoichiometric analysis, we established a mathematical model of the
measured spectral data and the corresponding blood glucose samples of known concentration, and the intensity of
the outgoing light after passing through the human body conformed to Lambertbeer's law:
A=lg(1/T)=Kbc
Fig 3. the Near-infrared optical glucose sensor
We transfected the plasmids encoding the complete insulin sequence into HEK 293T cells and nurtured them for a duration of 36 to 48 hours. Consequently, these modified cells released the protein into the surrounding medium, known as the supernatant. This represents the tailored system we devised for the secretion of insulin.To prevent excessively low blood glucose levels resulting from the continuous action of insulin, we linked sponge to the GIP promoter element to facilitate its expression. The multiple miRNA binding sites contained within sponge bind to various miRNAs, thereby inhibiting the negative regulatory effect of miRNAs on insulin mRNA.
miRNA effectively inhibits the expression of insulin, while upon the addition of sponge, the inhibitory effect of miRNA is significantly suppressed.
Fig 4. Regarding some of the experimental results of our system, more data can be found on the results wiki
To ascertain the expression level of insulin, we employed the luciferase gene, which was potentiated by 5xUAS, as a substitute for the insulin gene. By quantifying the bioluminescence intensity during the oxidation process of luciferin, we aimed to mirror the cellular secretion of luciferase, ultimately assessing the capability of our biological system under investigation to modulate luciferase secretion in response to varying blood glucose concentrations.
Fig 5. the structure of the pcDNA3.1-LucER plasmid, more data can be found on the parts wiki
Fig 6. the structure of the 5XUAS-Luc-miR-BS plasmid, more data can be found on the parts wiki