Under the premise that fluorescence signals can detect
nucleic acid signals, we hope to further optimize
our system, and enrich its functions through supporting software and hardware facilities, and promote its
application scenarios to thousands of households.
We changed the signaling element in the system from
ssDNA-F to PreP (colloidal gold particles after
crosslinking). In this way, theoretically, through the change of the color of the colloidal gold particles
solution, the change of its aggregation degree can be deduced, and then the amount of cleaved DNA can be
further obtained, realizing the measurement of miRNA concentration value.
By modifying -SH at both ends of 30nt single-stranded DNA,
we successfully achieved the cross-linking of
free colloidal gold particles in 20nm diameter through the formation of Au-S bonds, and the efficient
cross-linking can be seen under electron microscopy.
a
b
Figure 1. Image of colloidal gold particles under electron microscope
(a: precrosslinking; b: post-crosslinking)
The color of colloidal gold particles solution also
changed obviously before and after cross-linking. By
controlling the concentration ratio of colloidal gold particles before and after cross-linking in the
solution, we made a standard colorimetric card. In addition, through machine learning, our APP obtained
the ability to recognize different colors, that is, to recognize different concentrations of colloidal
gold particles solutions.
a
b
Figure 2. Color of colloidal gold particles
(a: precrosslinking; b: post-crosslinking)
Figure 3. Color of colloidal gold particles after crosslinking at different
concentrations
(From left to right, the concentration increases)
Our APP is very accurate at color recognition. When kit
users upload pictures to the APP, in addition to
the detection of the target miRNA concentration and the evaluation of the health status of the subjects,
they can also enjoy telemedicine services. With the improvement of the function of our APP, users can
conduct health consultation with the professional medical team of our school and affiliated hospitals in
real time through the APP in the future, so as to obtain the advice of professional doctors, early
prevention of diseases or timely diagnosis and treatment.
Figure 4. Telemedicine interface
The theoretical construction and design of software and
hardware have been completed, and the medical
resources we rely on are also very rich. Unfortunately, due to time constraints, the part of the colloidal
gold particles has not been completely completed. We will continue to improve this project, hoping to send
this detection system to every family in need, give full play to the value of our work, and help more
people in need of medical help.
