| The nanomaterials have attracted more interest in the study of researchers fromthe early1980s. The unique structure makes it has four effects: small size effect,surface effect, macroscopic quantum tunnel effect and quantum size effect.Nanoparticles with unique physical and chemical properties can be applied in the fieldof optical, electrical, biological technology, drug delivery, catalytical,magnetiematerials, etc. The combination of nanomaterials and fluorescence analysistechnology and combination of nanomaterials modified photoelectrodes andphotoelectrochemical (PEC) method to analyze the testing substance made themeasurement rapid and convenient.This paper will try to realize the incorporation of nanotechnology with PECanalysis technology and fluorescence analysis technology, which is applied topersistent organic pollutants (pops) and protein detection. The main contents are asfollows:(1) Label-Free PEC immunosensor based on CdTe/CdS co-sensitized TiO2nanotube array（NTA）structure for persistent organic pollutant-octachlorostyrene(OCS) detection: in this paper, we synthesis core/shell CdTe/CdS quantum dots (QDs)co-sensitized TiO2nanotube array, and probe deeply into its PEC performance. Basedon the ideal stepwise bandedge structure among them, the CdTe/CdS-TiO2NTAstherefore display excellent photo-electronic performance with a photocurrent densityof7mA/cm2in the visible region, making it a good PEC substrate. The anti-OCSantibody was modified on the photoelectrode throngh crosslinking agent, and then aPEC immunosensor was constructed for the selective quantitative analysis of OCS. IfOCS was introduced, the specific immunoreaction between OCS and the anti-OCSantibody forms immunocomplex hindering the transport of reduced reagent to thesurface of CdTe/CdS-TiO2NTA and leads to an obvious decrease in photocurrent. Wecan quantitatively analyze OCS through the photoelectric current signals. Underoptimal conditions, we successfully detected trace OCS in practical samples. OCS canbe detected in a liner range from5pM to50nM with the detection limit of2.58pM.The proposed label free PEC immunosensor exhibited good precision, sensitivity,selectivity, and storage stability, which embodies the prospect of application inmonitoring OCS in real samples. (2) We developed a novel fluorescent strategy for the detection of cytochrome Cbased on its unique DNA absorbing ability and universal quenching properties forfluorophores. As a transition metal dichalcogenides, single-layer VS2nanosheets witha sandwich structure display two outstanding properties which are similar to grapheneoxide: unique DNA absorbing ability and universal quenching properties forfluorophores. But since it had been developed, the two outstanding properties havenever been applied in analytical chemical field. In our experiment, we combinehydrothermal method with ultrasonic stripping method for the synthesis ofsingle-layer VS2nanosheets, which was developed in recent years.Introduce anaptamer (single-strand DNA) marked with fluorescein of cytochrome C. A single-layerVS2nanosheet exhibits different affinity toward aptamer versus the complex ofcytochrome C and the aptamer, the final performance is fluorescence quenching orrecovery. With the content of cytochrome C increasing, the fluorescence intensity alsoincreases: we can quantitatively analyze the cytochrome C through this method.Cytochrome C can be detected in a liner range from1.2207×10-8M to1.25×10-5Mwith the detection limit of0.8nM. The proposed method exhibited good precision,sensitivity, selectivity and a wide liner range. The proposed strategy is simple andcost-effective, which might provide a promising method of choice for convenientcytochrome C detection. |
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