Design Synthesis And Performance Research Of Several Nanoprobes

Nanomaterials refer to a material that have at least one dimension(0.1-100 nm)in a three-dimensional space or consists of nanoparticles as a basic unit.With the progress and rapid development of modern nanoscience and other nanotechnologies,nanomaterials have attracted great attention and have been used in different fields such as energy,environment,food industry and medicine.Nanomaterials,because of its small size and has many features,which is based on excellent biocompatibility and the unique optical properties make nanomaterials research value and the analysis of the sensing area has huge development space,the current nanomaterials have been widely applied to the cell/live imaging,life active material analysis,environment monitoring,etc.With the increasing of human activities,the discharge of environmental pollutants has gradually increased,and the accompanying environmental pollution has seriously endangered human health.Among them,the abuse of organic pollutants represented by tetracycline antibiotics(TCs)and the harm of inorganic pollutants represented by heavy metal ions Hg²⁺are very serious.Therefore,there is an urgent need to develop a detection platform for TCs and Hg²⁺.Based on this,the paper proposed the use of nanomaterials to construct nanoprobes for the detection of TCs and Hg²⁺.Nanoprobes based on nanomaterials are not only environmentally friendly,but also have the characteristics of simple synthesis and high sensitivity.The specific research work is as follows:(1)Bovine serum albumin(BSA)-capped gold nanoclusters(BSA-AuNCs)were synthesized,and the red luminescence of BSA-AuNCs was used as a reference signal.At the same time,BSA has a fluorescence sensitization effect on TCs,Therefore,based on the selective sensitization of BSA to doxycycline(DC),BSA-AuNCs can be used to construct a nanometer ratio sensor for selective detection of DC.DC,a semisynthetic tetracycline antibiotic,possesses better antibacterial activity,stronger penetrating power,wider distribution,higher bioavailability and longer elimination half-life than natural tetracycline antibiotics.As a consequence,DC has been widely applied in animal husbandry as a feed additive to promote the animal growth,while the consequent DC residues in animal-derived foods such as meat,milk and egg cause serious threat to the human health.Therefore,it is significant to develop efficient methods for monitoring the concentration of DC in animal-derived foods.The ratiometric nanoprobe based on BSA-AuNCs for DC selective detection has the advantages of simple synthesis(one-pot method),short response time(1 min),and low detection limit(36 n M).At the end of this work,BSA-AuNCs was used to detect DC in fish samples to improve the practical applicability,and a test strip was further made for convenient use.Therefore,in this work,a ratiometric nanoprobe with high selectivity for DC detection is proposed in this work.(2)A highly sensitive ratiometric nanoprobe composed of BSA and ZIF-8 was synthesized,which combined the fluorescence and scattering signals of DC and Zn²⁺in ZIF-8 could induce the decomposition of DC,resulting in the decrease of the second-order scattering(SOS).Meanwhile,ZIF-8 and BSA had dual fluorescence sensitization effect on DC,which could lead to the enhancement of the fluorescence signal.Thus,a ratiometric nanoprobe with high selectivity and sensitivity for DC detection was constructed.Based on the selective fluorescence sensitization of BSA,the probe can selectively detect DC in TCs,and the dual sensitization of BSA and ZIF-8 can greatly improve the detection performance.This probe provides a new strategy for the construction of a DC ratiometric sensor,and a ratio sensing platform with high selectivity and sensitivity(3.4 n M)was developed for the detection of DC in animal-derived foods.At the end of this work,the ratiometric sensor was used to detect DC in fish and milk samples to improve the practical applicability.Therefore,in this work,a new strategy is proposed to design a ratiometric nanoprobe that can detect DC with high selectivity and sensitivity among other TCs.(3)A highly sensitive colorimetric nanoprobe composed of MnO₂ nanosheets and monothioglycerol(MTG)was synthesized.The probe was based on MnO₂ nanosheets that could be decomposed into Mn²⁺by reducing substances(sulfhydryl compounds,H₂O₂ and ascorbic acid).Thus,the color changes and the sulfhydryl group with Hg²⁺to form Hg-S,which can inhibit the decomposition of MnO₂ nanosheets and construct a comparable colorimetric nanoprobe for detecting Hg²⁺.As one of the most toxic heavy metal ions,Hg²⁺is usually enriched into the human body through the food chain to hinder the normal activities of human cells.Therefore,there is an urgent need to develop a visual and high sensitivity probe for Hg²⁺detection.The colorimetric probe for detecting Hg²⁺constructed by combining MnO₂ nanosheets and MTG has the advantages of simple synthesis(one step reaction at room temperature)and low detection limit(0.7?M).The probe has been successfully used to detect Hg²⁺in tap water.Moreover,the probe has been further made into test strips for convenient use.Therefore,this work has developed a simple and sensitive colorimetric nanoprobe for Hg²⁺detection,which provides hope for the detection of Hg²⁺in the environment in the future.