Single-Molecule Detection of Nucleic Acids via Liposome Signal Amplification in Mass Spectrometry.

Juan Long,Xiangcheng Lin,Lixian Sun,Mingyue Li,Mengmeng Zhao,Fang Yu,Fen Xu,Jing Zhang

doi:10.3390/s22041346

Juan Long, Xiangcheng Lin + Show 6 more

Open Access

https://doi.org/10.3390/s22041346

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Abstract

A single-molecule detection method was developed for nucleic acids based on mass spectrometry counting single liposome particles. Before the appearance of symptoms, a negligible amount of nucleic acids and biomarkers for the clinical diagnosis of the disease were already present. However, it is difficult to detect extremely low concentrations of nucleic acids using the current methods. Hence, the establishment of an ultra-sensitive nucleic acid detection technique is urgently needed. Herein, magnetic beads were used to capture target nucleic acids, and liposome particles were employed as mass tags for single-particle measurements. Liposomes were released from magnetic beads via photocatalytic cleavage. Hence, one DNA molecule corresponded to one liposome particle, which could be counted using mass spectrometric measurement. The ultrasensitive detection of DNA (10–18 M) was achieved using this method.

Highlights

Long, J.; Zhang, J.; Yu, F.; Xu, F.; Sun, As one of the basic life molecules, nucleic acids play a pivotal role in the storage, transmission, and expression of genetic information
Liposomes are usually vesicles of varied beads labelled with the trapping probe and 5 μL of liposomes labelled with the optical sizes, with particle sizes ranging from tens to thousands of nanometres
Phosphatidylcholine phospholipids are ionised in ESI, with high sensitivity for mass spectrometry detection

Summary

Introduction

J.; Zhang, J.; Yu, F.; Xu, F.; Sun, As one of the basic life molecules, nucleic acids play a pivotal role in the storage, transmission, and expression of genetic information. Nucleic acid detection is performed via signal amplification methods. Other available techniques include the rolling circle amplification reaction (RCA) [4,5], the hybridisation chain reaction (HCR) [6], and loop-mediated isothermal amplification (LAMP) [7,8,9]. These techniques present a series of limitations. The sensitivity of RCA is close to that of PCR, and the equilibrium time of RCA is about 6 h. The equilibrium time of LAMP is about 1 h, and the sensitivity of LAMP reaches the level of PCR. The major problem with LAMP is that it cannot perform multiplex amplification

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