Study Of Novel Sensitive Detection Method For Ovarian Cancer

Noble metal nanoparticles are a kind of metal materials that are of low cost,easy to prepare and convenient to make use of.However,they have specific physical and chemical properties which can be utilized generally in the fields of biochemical detection,medicine,health and environment protection.In the field of biochemical and environmental detection,some important matters are often in trace amount which are hard to analyze by usual method.To detect these trace substances,enzymes are often taken advantage of in the design of biosensors to construct multiple signal amplification system.Combining both the merits of noble metal nanoparticles and enzymes to build biosensors,we can avoid the use of toxic fluorochrome and achieve higher sensitivity.In this article,we integrate the noble metal nanoparticles into the enzyme based signal amplification design and then realize the highly sensitive detection of tumor biomarkers.1.Ultrasenstive and Feasibly Achieved Protein Detection Based on the Integration of Three Signal Amplification Reactions via Sharing a DNA Sequence.We report here a novel strategy for the detection of proteins based on the integration of three signal amplification reactions via sharing a specially designed DNA sequence.In this strategy,the shared-sequence is firstly designed to be enclosed in a hairpin probe named as HP1.In the presence of the target protein,it will interact with the target,since the probe is also designed to have the aptamer sequence of the target protein,thus the shared-DNA is exposed.Then,the HP1 probe binds with another hairpin probe named as HP2,and subsequently the conformation of HP2 is rearranged to initiate a strand displacement reaction.Consequently,the shared-sequence is replaced and released to trigger more amplification cycles.In the meantime,more and more copies of the shared-sequence are generated as the successive triggers for the similar amplification reactions.As a result,three signal amplification reactions are intergared and performed simoutaniously by using the same set of nicking enzyme and polymerase,all of which are due to the presence of the target protein.Meanwhile,a great number of signaling strands can be generated,thus lots of fluorescent silver nanoclusters can be obtained,leading to remarkable signal readout for the detection of the target protein.This strategy has also been demonstrated by the assay of human tumor necrosis factor-alpha.The developed method for the assay of this tumor marker protein is then employed to analyze serum samples from ovarian cancer patients,showing potential clinical application of this method.2.Highly Sensitive Protein Detection Based on Smart Hybrid Nanocomposite-Controlled Switch of DNA Polymerase ActivityIn this work,we have successfully designed a smart and flexible signal amplification method based on a newly synthesized hybrid nanocomposite with switchable enzyme activity for specific and sensitive protein detection.The smart hybrid nanocomposite synthesized here is initially loaded with quenched fluorophore and a unique aptamer-inhibited DNA polymerase.It then undergoes target protein-triggered release of the fluorophore and activation of the DNA polymerase,which can thereby promote multiple catalytic reactions and recycled use of the target protein,resulting in the generation of highly amplified signals.Therefore,a small amount of target protein can lead to a large amount of signal without being consumed.In addition,the programmable control of DNA polymerase activity may effectively reduce background signal and avoid false positive results,which may further facilitate an efficient detection of small amounts of protein.By taking the detection of human stress-induced phosphoprotein 1(STIP1)as an example,the excellent performance of this method has been verified.Furthermore,the proposed method has been used to analyze serum STIP1 from patients of ovarian cancer,showing promising application in clinical practice.