The Application Of Dark-Field Light Scattering Characteristics Of Plasmonic Gold Nanoparticles In Hepatitis Virus Nucleic Acid Detection

As one of the most serious public health problems in the world,viral hepatit is an important cause of global liver disease at present,threatening people’s life safety and health seriously.As an important disease marker,hepatitis virus nucleic acid is of great significance to the judgment of infectivity and replication level of hepatitis virus and the evaluation of drug treatment effect.With the development of analytical technology,a variety of sensor platforms for detection of hepatitis virus nucleic acid,such as real-time fluorescence polymerase chain reaction analysis,colorimetry,fluorescence,inductively coupled plasmon mass spectrometry and electrochemical methods,have been reported at present.However,there are still problems such as insufficient sensitivity,low specificity,low accuracy and difficulty in detecting actual samples.Therefore,it is urgent to develop simple,sensitive and accurate detection strategies for hepatitis virus nucleic acid.Gold nanoparticles(AuNPs)are widely used in biochemical analysis,bioimaging and other fields because of the excellent properties of localized surface plasmon resonance(LSPR).Its scattering properties are affected by many factors such as the size,morphology,microenvironment of particles.At present,etching,assembly and other methods are the main ways to adjust the scattering signals and build analytical sensing systems.Therefore,this article aims to develop more sensitive and accurate hepatitis virus nucleic acid detection platforms.The specific contents are as follows:1.Highly sensitive plasmonic biosensor for hepatitis B virus DNA based on the surface etching of the helical gold nanorods.As an important disease marker,hepatitis B virus nucleic acid(HBV-DNA)is of great significance in the early diagnosis and clinical treatment of hepatitis B.However,due to the low content in clinical samples,it is challenging to develop more sensitive detection platforms.Based on the surface etching of helical gold nanorods(HGNRs),a highly sensitive detection strategy for HBV-DNA was developed by dark field microscopy(DFM)technology.This work utilized HGNRs with high surface activity as the light scattering probe.With the increase of target concentration,the probe was gradually etched,resulting in the regular change of scattering signal,which was more sensitive than ordinary gold nanorods.Introducing hybrid chain reaction(HCR)to amplify reaction signal,the limit of detection(LOD)of this strategy was as low as30.15 f M(3σ/k).Moreover,the proposed strategy offered the good specificity,which was capable of distinguishing mismatch sequences and other viral nucleic acids.This strategy is universal and can be extended to the detection of other viral nucleic acids only through simple sequence modification,providing new ideas for the detection of other types of various DNA disease markers.2.“Hepatitis virus indicator”----the simultaneous detection of hepatitis B and hepatitis C viruses based on the automatic particle enumeration.As the common hepatitis B virus(HBV)and hepatitis C virus(HCV)are important causes of liver diseases,which greatly threaten human health and public hygiene.Due to the similar transmission routes of HBV and HCV,it is highly susceptible to suffer from the cross-infection of them.So it is urgent to develop strategies with high sensitivity to distinguish HBV/HCV and detect their overlapping infection.Herein,this study developed a new biosensor named “hepatitis virus indicator” for simultaneous detection of HBV and HCV based on the automatic particle enumeration by the combination of Exo Ⅲ assisted signal amplification strategy and particle counting technology with a DFM.The limit of detections(LOD)were as low as 0.194 p M for HBV and 0.169 p M for HCV,respectively,which showed high sensitivity.In addition,the proposed method was capable of simultaneously detecting HBV and HCV based on the colorful light scattering from plasmonic nanoparticles.The proposed assay is simple,sensitive,selective for the simultaneous detection of HBV-DNA and HCV-DNA and it is universal,which provides a new idea for the early diagnosis of diseases.In a word,taking DFM as the basic mean and AuNPs as light scattering probes,this paper makes full use of LSPR property to build highly sensitive detection platforms for hepatitis virus nucleic acid,and realizes the simultaneous detection of multiple targets,which provides a new way for the early diagnosis of viral hepatitis.