Construction And Application Of Fluorescent Sensing Probes Based On Metal Oxide And Au Cluster Nanomaterials

Detection of toxic ions and disease-related markers is particularly important in environmental protection monitoring and disease diagnosis.The construction of fluorescent probe with simple operation,non-toxic and low price,fast response,high sensitivity and selectivity has become one of the hot spots in analytical sensing field.In this paper,the construction and response mechanism of the fluorescent probes based on some nano-quenchers and fluorescent reagents have been reviewed in detail.In order to further develop new,efficient,and inexpensive nanoquenchers and functional luminescent materials,and develop fluorescent probes with low background,high signal-to-noise ratio,and high sensitivity for analytical applications in environmental monitoring and biomedical diagnosis.The following two aspects of work are carried out:Firstly,we explored the interaction of some transition metal oxide nanomaterials with the simple and easy organic small molecule dyes,and developed some simple,high sensitivity and good selectivity probe for analytical application.Secondly,based on the relevant mechanism of Au nanocluster fluoresce origin,we explore the effects of Au nanocluster and active molecules and biomolecules,and developed fluorescence method and performance fluoresce probe.The main research contents are as follows:1.We explored the role of Fe₃O₄ NPs with commercial fluorescein（FAM）and fluorescein-labeled single-stranded DNA（FAM-ssDNA）.Results show that Fe₃O₄ NPs can efficiently adsorb FAM-ssDNA and effectively quench the fluorescence of FAM through excited state electron transfer.On this basis,we developed the Fe₃O₄ NPs/FAM-ssDNA for pyrophosphate anions（PPi）detection by the competition and cooperation effect.Compared with some fluorescence sensing methods,this platform is not only simple in design,easy to operate,but also has excellent selectivity for PPi over other phosphate-containing compounds.Under optimized conditions,the detection range is 0.20-4.0μM,and the detection limit is 76 nM.The method was successfully applied to the determination of PPi in the synovial fluid.2.We explored the effect of the CeO₂ nanowire and commercial probes BODIPY,ATP-BODIPY,riboflavin（Rf）,and riboflavin phosphate（Rf-P）.The experimental results demonstrate that CeO₂ nanowire may act as an efficient quencher for small fluorescent molecules with a phosphate group,BODIPY-ATP and Rf-P.Based on the similarity between arsenate and phosphate and the performance of ATP-BODIPY,we developed a CeO₂ nanowire-BODIPY-ATP platform for highly selective and sensitive detection of arsenate.Under the optimized condition,the detection limit was as low as 7.8 nm.The proposed method had been successfully employed for determination of arsenate in real water samples.The establishment of this platform expanded the application of CeO₂ in fluorescence sensing analysis.3.We explored the effects of FeOOH QD and commercial probe ATP-BODIPY and GSH.Results show that FeOOH QD has an excellent and rapid quenching effect for ATP-BODIPY,and can be reduced to Fe²⁺by GSH.Based on this foundation,we developed FeOOH QD-ATP-BODIPY probe for GSH analytical applications.Under the optimized experimental conditions,a good detection limit 68.8 nM and excellent linear range width 0.2-400μM were successfully established.Selectivity for GSH was also exhibited.It was used for the determination of GSH in serum samples.Meanwhile,the imaging ability of FeOOH QD-ATP-BODIPY was explored for intracellular GSH in situ.This research expands the application of FeOOH nanomaterials in the fields of fluorescence sensing and cell biology.4.We explore the effects between MnO₂ nanosheets and Perylene probe,and develop MnO₂nanosheet-Perylene probe for an alkaline phosphatase（ALP）determination with the aid of L-ascorbic acid-2-phosphate（AAP）.Under the optimized conditions,an excellent linear range of 1-80 mU/mL the detection line 0.53 mU/mL was obtained.It also had excellent applicability in human serum samples.This sensing platform not only has high sensitivity,easy operation,but also has the advantages of small sample usage.5.We explored the fluorescence effect of hydroxyl radicals（·OH）and H₂O₂ on AuNCs protected by bovine serum albumin（BSA-AuNCs）,and established BSA-AuNCs-H₂O₂ system for the fluorescence determination of Fe²⁺by the efficient Fenton reaction.Under optimized conditions,excellent linear relationship was achieved in the concentration range of 0.080-2.5μM and 5.0-100μM,the detection limit（LOD）reached 24 nM.It was successfully used for the determination of Fe²⁺in rat cerebrospinal fluid.6.Inspired by the interaction between guanidine groups of arginine and substrates in biological systems,we explored the effects of Gua and Arg on ATT-AuNCs fluorescence and chirality.Experiments results show that it can effectively enhance the fluorescence of ATT-AuNCs.Importantly,the chiral Arg can induce the chiral optical activity of ATT-AuNC.The experimental results provide a new method for the preparation of ultrabright and chiral AuNCs.