Measurement of bilirubin concentration in blood samples
A method for measuring bilirubin concentration in a sample includes preparing a sensing element, where the sensing element may include a plurality of carbon dots, adding the sample to the sensing element, where the sample may include a plurality of bilirubin molecules, obtaining a first grayscale image of the sensing element under ultra-violet (UV) irradiation, irradiating visible light with a wavelength between 470 nm and 490 nm on the sensing element, obtaining a second grayscale image of the sensing element under ultra-violet (UV) irradiation, calculating a light intensity difference by calculating a difference between a first average light intensity of the first grayscale image and a second average light intensity of the second image, and determining the bilirubin concentration based on a correlation between the bilirubin concentration and the light intensity difference.
1. A system for measuring bilirubin concentration in a sample, the system comprising:
a testing chamber comprising a light-tight enclosure;
a sensing element removably disposed within the testing chamber, the sensing element comprising:
a bacterial cellulose nanopaper; and
a plurality of carbon dots embedded within the bacterial cellulose nanopaper,
wherein a top surface of the sensing element is configured to hold a deposit of the sample;
at least one UV light source disposed within the testing chamber, the at least one UV light source configured to irradiate UV light onto the top surface of the sensing element;
at least one visible light source disposed within the testing chamber, the at least one visible light source configured to irradiate visible light with a wavelength between 470 nm and 490 nm onto the top surface of the sensing element;
an image capturing device disposed within the testing chamber, the image capturing device configured to capture images of the top surface of the sensing element; and
a processing unit coupled with the at least one UV light source, the at least one visible light source, and the image capturing device, the processing unit comprising:
one or more processors; and
a non-transitory computer readable medium coupled with the one or more processors, the non-transitory computer readable medium configured to store executable instructions to cause the one or more processors to:
irradiate the top surface of the sensing element with UV light by turning the at least one UV light source on;
obtain a first image of the top surface of the sensing element utilizing the image capturing device;
irradiate the top surface of the sensing element with visible light by turning the at least one visible light source on for a duration between 1 and 10 minutes;
obtain a second image of the top surface of the sensing element utilizing the image capturing device;
convert the first image to a first grayscale image;
convert the second image to a second grayscale image;
calculate a first average light intensity of the first image by averaging light intensities of a plurality of pixels of the first image;
calculate a second average light intensity of the second image by averaging light intensities of a plurality of pixels of the second image;
calculate a light intensity difference by subtracting the first average light intensity from the second average light intensity; and
wherein the non-transitory computer readable medium further stores a correlation between the light intensity difference and the bilirubin concentration, the processor further configured to determine the bilirubin concentration based on the correlation between the bilirubin concentration and the light intensity difference.
2. The system according to claim 1 , wherein the correlation between the bilirubin concentration and the light intensity difference defined by:
Δ S= 2.772 C+ 5.664,
wherein ΔS denotes the light intensity difference, and
wherein C denotes the bilirubin concentration in mg dL −1 .