Detection Of MiRNA And PARP-1 Based On The Nanomaterials

The detection of cancer biomarkers can be used to determine whether there is cancer.As people continue to study the cause and development of cancer,more and more cancer biomarkers have been discovered,making the early diagnosis of cancer possible.Early diagnosis of cancer plays an important role in the treatment of cancer.The earlier diagnosis and treatment of cancer make the survival rate of cancer patients significantly improved.In order to achieve this goal,this article explores the detection methods of cancer biomarkers such as poly（ADP-ribose）polymerase-1 and mi RNA,by mesoporous silicon films,gold nanoclusters,strand displacement amplification reaction and analogical catalytic hairpin assembly reaction.The detection method realizes the label-free,dual mode detection for poly（ADP-ribose）polymerase-1and multiple detections of mi RNA.The main contents of this paper are as follows:1.Ultrasensitive and specific multiple mi RNAs detection based on strand displacement amplification and analogical catalytic hairpin assemblyIn this work,we developed an ultrasensitive and specific multiple mi RNAs detection strategy based on strand displacement amplification（SDA）reaction and analogical catalytic hairpin assembly（ACHA）reaction.The target mi RNA specifically binds with template and initiates the SDA reaction to produce abundant amplification products（triggers）,which take part in the ACHA reaction on the electrode surface resulting in a decreased electrochemical response.With the help of dual amplification strategies,the linear relationship between the electrochemical signal and mi RNA-122 and mi RNA-21 concentration was in the range of 0.1f M to 10 f M,with the detection limit of 0.012 f M and 0.075 f M,respectively.The electrochemical sensor can also be applied to detect other mi RNA just by changing the template strands.In addition,the electrode can be regenerated by incubating with specific DNA strands.2.Label-free poly（ADP-ribose）polymerase-1 activity assay based on positively charged mesoporous silica filmsIn this work,a label-free electrochemical（EC）biosensor for PARP-1 activity detection was developed based on the electrostatic attraction between negatively charged poly（ADP-ribose）（PAR）and positively charged mesoporous silica films（NH₂-MSFs）.The negatively charged PAR adsorbed on the NH₂-MSFs surface effectively,which prevented the electroactive probe reach to the ITO electrode and resulted in the decreased electrochemical signal.The electrochemical signal decreased linearly with the increment of PARP-1 in the range of 0.01 U to 1.2 U with a detection limit of 0.005 U,the result is comparable or superior to the reported PARP-1 biosensor.The method has also been successfully applied to detect the PARP-1 activity in human serum,cancer cells,and evaluate of PARP-1 inhibitors.This sensing platform showed merits of simplicity and easy manipulation.3.Dual-mode detection of PARP-1 by fluorescence and chemiluminescenceIn this work,a dual-mode,label-free strategy for detection of PARP-1 with gold nanocluster（Au NCs）was developed.Firstly,we modified magnetic beads（MBs）with specific ds DNA（ds DNA-MB）.Then PARP-1 was active by ds DNA and catalyzed the synthesis of negatively charged poly（ADP-ribose）（PAR）.Because of the strong electrostatic interaction between PAR and positively charged Au NCs,abundant Au NCs were adsorbed to produce strong fluorescence（FL）and to catalyze the luminol-H₂O₂ system,producing strong chemiluminescence（CL）.According to the generated FL and CL signals,PARP-1 has been detected sensitively ranging from 0.01 U to 1.0 U,and the limit of detection（LOD）is estimated to be 0.009 U and 0.007 U,respectively.Moreover,this dual-mode strategy was available to evaluate inhibitors and distinguish cancer cells with approving results.Thus,this method opened a new avenue for clinical diagnosis and inhibitor research in the future.