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DNA-Sequencing Platform Based on Light-Guiding Nanowires

Yu, Eric (2024) MOBM02 20241
Degree Projects in Molecular Biology
Popular Abstract
From Strands to Wires

All the genetic information required to develop and maintain an organism is packed tightly into the molecule known as DNA. Determining the order of the four bases, which are the building blocks of DNA, enables the identification of a DNA segment. Modern disease diagnostics use this identification method, known as DNA sequencing, to inspect genetic integrity. Thus, it is vital to develop tools that can accurately sequence the DNA base order.

Today, there are various DNA sequencing methods that involve a polymerase chain reaction (PCR) step, which generates multiple copies of a given DNA template. However, PCR is error-prone and thus it is preferred to be omitted from DNA sequencing.

Here, we explore how the... (More)
From Strands to Wires

All the genetic information required to develop and maintain an organism is packed tightly into the molecule known as DNA. Determining the order of the four bases, which are the building blocks of DNA, enables the identification of a DNA segment. Modern disease diagnostics use this identification method, known as DNA sequencing, to inspect genetic integrity. Thus, it is vital to develop tools that can accurately sequence the DNA base order.

Today, there are various DNA sequencing methods that involve a polymerase chain reaction (PCR) step, which generates multiple copies of a given DNA template. However, PCR is error-prone and thus it is preferred to be omitted from DNA sequencing.

Here, we explore how the vertically aligned rod-like structures called nanowires could be used as a novel platform for DNA sequencing. Nanowires have a diameter within the nanometer scale and are regarded as highly sensitive tools. The surface of nanowires can be modified by immobilizing compounds that are able to capture molecules of interest near the surface. Particularly, nanowires made of semiconductor materials are useful since they can conduct light from a surface-bound fluorescent molecule. This conducting property is called the light-guiding effect due to the nanowire guiding the light emitted by a fluorescent molecule towards the nanowire’s tip. However, a requirement for the signal to be enhanced is that the fluorescent molecule is within a region close enough to the nanowire surface.

We created a combination of surface molecules that were able to bind different lengths of fluorescently labelled DNA strands at different concentrations. The lengths ranged from 25 to 1996 base pairs long of DNA strands, which is more than five times larger than the nanowire diameter. Fluorescent images were taken of the nanowires to analyze their quantity and signal intensities. We found that the longest available DNA strand generated the most signal meaning that even longer DNA strands can be implemented in nanowire usage at low concentrations.

In this study, we have created a platform with a surface chemistry that can enhance fluorescent signals from long DNA strands at low concentrations. Based on these findings, a DNA sequencing enzyme can be added to a surface-bound strand in combination with light emitting bases to generate long DNA segments during the sequencing process.



Master’s Degree Project in Molecular Biology 30 credits 2024
Department of Biology, Lund University
Advisor: Heiner Linke
Division of Solid State Physics, Department of Physics (Less)
Please use this url to cite or link to this publication:
author
Yu, Eric
supervisor
organization
course
MOBM02 20241
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
9176788
date added to LUP
2024-10-18 11:58:34
date last changed
2024-10-18 11:58:34
@misc{9176788,
  author       = {{Yu, Eric}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{DNA-Sequencing Platform Based on Light-Guiding Nanowires}},
  year         = {{2024}},
}