| Cancer, also known as malignant tumor, it has been threatening human health and life, brings people with increasingly serious physical and psychological burden. Antitumor drug use for clinical treatment of cancer has brought a new dawn, but the use and residual of the drug also can cause damage to the normal organs. Along with the in-depth study of antitumor drugs, found that many anticancer drugs with DNA have specific interactions. Therefore, building all kinds of new type of DNA biosensor for screening of antitumor drug, qualitative and quantitative analysis gets more and more attention. In recent years, new nanomaterials such as gold nanoparticles and graphene, have been widely recognized because of their nanosize effect, superquenching performance, resonance light scattering, biocompatibility and low toxicity. Based on the specific interactions of DNA and nanomaterials, construction of optical sensing platform for analysis has a good application prospect.This paper is divided into four chapters:Chapter1IntroductionFirst this work systematically introduces the definition, working principle, classification, development history and prospect and outlook of biosensors. Then it introduces the working principle, types and application of DNA biosensors, and focus on the electrochemical DNA biosensors and fluorescence of DNA biosensors. Then, about the new nanomaterials, gold nanoparticles (AuNPs) and graphene, special DNA secondary structure G-quadruplexes in the application of the optical sensor. Finally, anti-cancer mechanism of antitumor drug bleomycin (BLM) and coralyne and the mechanism of their interactions with DNA were raised.Chapter2Simple colorimetric sensing of trace bleomycin using unmodified gold nanoparticlesA simple colorimetric sensing platform for trace bleomycin (BLM) was proposed with the unmodified gold nanoparticles (AuNPs) as the sensing element. BLM has multiple N-donor functionality and exhibited strong coordination effect on AuNPs, which made it possible for the occurrence of ligand exchange of BLM with the weakly surface-bound citrate ions on AuNPs. Meanwhile, BLM acted as a molecular linker, leading to a close proximity between each AuNPs. Thus the citrate ion-stabilized AuNPs was efficiently crosslinked by BLM molecules, which was reflected by the obvious color change from wine red to blue and rapid aggregation kinetics within7.5min. The BLM sensing based on unmodified AuNPs can be seen with the naked eye and monitored by UV-vis extinction spectra. The linear range of the colorimetric sensor for BLM was from2to150nM. The as-established colorimetric strategy opened a new avenue for trace BLM determination.Chapter3A sensitive graphene oxide-DNA based sensing platform for fluorescence "turn-on" detection of bleomycinA sensitive and selective fluorescent sensing platform for bleomycin (BLM) was developed based on BLM-induced DNA strand scission and the difference in affinity of graphene oxide for single-stranded DNA containing different numbers of bases in length. BLM-induced DNA strand scission was complete within5min, which contributed to the sensitive detection of BLM. The detection limit is0.2nM, and the recoveries of serum samples analysis were satisfactory.Chapter4Label-free colorimetric detection of coralyne based on peroxidase-like split G-quadruplex DNAzymeA simple design of label-free colorimetric sensor for coralyne was demonstrated based on the coralyne-modulated peroxidase-like split G-quadruplex DNAzyme via A2-coralyne-A2coordination. A linear response from0.06to10μM was obtained for coralyne. The detection limit was estimated to be19nM. The proposed protocol was sensitivity, rapid, cost-effective and easy operation. So, this method is expected to apply for point-of-care testing and provide a new platform for drug screening. |
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