Probe Design And Photoelectrochemical Nucleic Acid Analysis Based On Low-toxicity Multivariate Semiconductor Nanomaterials

The development of new bioanalysis techniques with high sensitivity,rapid speed and good specificity is of great significance in many fields such as disease diagnosis,medical research,environmental monitoring and food safety,etc.Among the many biomolecule detection methods,photoelectrochemical(PEC)bioanalysis is a new method that has developed rapidly in recent decades.The combination of bioanalysis technology and photoelectrochemical sensing technology has obvious advantages and potentials,has unlimited possibilities for sensitive and accurate photoelectrochemical bioanalysis and detection.The basic principle of PEC bioanalysis is to irradiate light on a specific photosensitive material to convert the material to photoelectric,so that the biochemical information of the concentration of the analyte is converted into electronic information of readable signals through the transducer.So far,many photoactive species have been used for specific and sensitive biomolecular detection.One of the most important parts of constructing photoelectrochemical sensor is photoelectric active material.Now,with the rapid development of photoelectrochemical biosensing technology,the demands of people for highly efficient,novel,environmentally friendly photoelectrochemical are also increasing.In general,binary semiconductor compounds have a wide range of applications,but multivariate semiconductor compounds have more unique properties than them,especially in the field of photoelectrochemical aspect.Most of the components of multiple inorganic semiconductors are low toxicity,and the proportion and size of the elements can be adjusted during the synthesis process to achieve the coordination of the band gap of the material,thus improving the absorption coefficient of the material in the visible or near-infrared light region,and constructing the biosensor with excellent performance.And through various probes designed strategies to amplify the signal changes of photoelectrochemical sensing,further improve the analysis performance of photoelectrochemical biosensor.In this paper,the low toxicity of multiple inorganic semiconductor composites as photoelectrochemical active materials,around the construction of photoelectrochemical sensors with high sensitivity and low detection limit,the following two photoelectrochemical biological analysis platforms were designed:1.In this study,the photoelectrochemical sensor based on a porous ferroferric oxide functionalized probe and low toxicity quad semiconductor material was designed to sensitively analyze and detect mi RNA-155.The photoelectrochemical substrate material in the sensor was a low toxic quaternary semiconductor Cu₂Zn Sn S₄.The synthesis of porous magnetic Fe₃O₄NPs was simple and had the appropriate pore size to load the photosensitizer.The photosensitizer was sealed with the complementary capture probe DNA of the target mi RNA to form a functionalized probe based on porous Fe₃O₄NPs.The applied Fe₃O₄NPs was not only uniformly distributed,but also had magnetic properties,which could be easily separated.In addition,most of the current photoelectrochemical biosensors involved the process of fixing the recognition probe or signal probe to the electrode,which inevitably required complex experimental steps and might lead to poor reproducibility.In this work,the prepared porous Fe₃O₄NPs material integrated the recognition probe and the signal probe to perform photoelectrochemical analysis of the target without any fixed procedure,simplifying the experimental procedure and making the biometric identification process more adequate.In addition,the probe design of double stranded specific nuclease catalyzed nucleic acid amplification was added and used for target cyclic amplification,so it was expected to achieve ultrahigh sensitivity mi RNA analysis.2.In this work,we prepared ternary inorganic semiconductor nanomaterial spinel Zn Fe₂O₄as photoelectrochemical active material.It is a low-toxicity n-type semiconductor with peroxidase activity itself,which can be used as a nanoenzyme to catalyze hydrogen peroxide(H₂O₂)decomposition.In this article,we proposed a novel biosensor which integrated natural enzyme and photoactivated nanoenzyme in the same interface,and used the coexisting substance as the photocontrolled signal output converter to construct a switchable biosensor of colorimetric and photoelectrochemical.The natural enzyme horseradish peroxidase(HRP),the nanoenzyme Zn Fe₂O₄,and the coexistence H₂O₂were used as models to verify the concept.In the“no light”state,H₂O₂actd as a substrate in the reaction of HRP and2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS),so it could be used for quick on-site colorimetric observation.In the“light”state,the separation of electrons and holes could not be carried out in HRP,but Zn Fe₂O₄had excellent efficiency of separation of electrons and holes,and showed good photoelectrochemical performance compared with HRP.In this state,H₂O₂acted as the electron acceptor of Zn Fe₂O₄,which could amplify the photoelectric signal again.The switchable dual-mode biosensor strategy demonstrates versatility,scalability,and more sensitive results.