Research On Detection Of Harmful Substances Based On Silicon Quantum Dots Fluorescence Sensor

As the public health awareness continues to increase,the safety requirements for foods and the like are also increasing.In order to meet the accurate and rapid detection of residual harmful substances in food,it is necessary to develop new detection techniques.In this context,research on nanosensor detection technology is receiving widespread attention.The paper is based on the detection of several common harmful substances?hypochlorite,hydroquinone and hydrogen peroxide?in drinking water,through theoretical analysis and experimental research,based on silicon quantum dot nano-sensitive materials and new sensing technology.Fluorescent silicon quantum dots with excellent optical properties are designed and designed to be simple,fast,highly sensitive and highly selective.The main contents are as follows:1.Introducing N-[3-?trimethoxysilyl?propyl]-ethylenediamine)and catechol as initial reactants to synthesize silicon quantum dots?SiQD?with excellent properties by simple hydrothermal method).The morphology and structure of the quantum dots were characterized by transmission electron microscopy,Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy.Silver nanoparticles can quench the fluorescence of SiQD due to surface energy transfer?SPEET?from SiQD?donor?to silver nanoparticles?receptors?.After the addition of hypochlorite?ClO^-?,ClO^-is capable of etching silver nanoparticles,thereby releasing SiQD and restoring the fluorescence of SiQD.The sensing system has many advantages,such as a wide linear detection range,high sensitivity and excellent selectivity.Under optimal conditions,the linear range for ClO^-detection is 0.1?M-100.0?M and the detection limit is 0.08?M.2.A novel nano-sensing platform was successfully developed by simple hydrothermal method for preparing catechol?CC?-stabilized silicon quantum dots?C-SiQDs?and using C-SiQDs as catalysts and fluorescent indicators.Hydroquinone?p-DHB?was detected sexually.In the process of detecting p-DHB,C-SiQDs can catalyze the oxidation of p-DHB to form benzoquinone?BQ?.The formation of BQ causes the color of the solution to change from light yellow to dark brown and BQ can effectively quench the fluorescence of C-SiQDs.For the interfering substance CC,since it has a large effect on the CC steric hindrance of the surface of the quantum dot,it cannot contact the surface of the C-SiQD,thereby limiting the oxidation of the CC and the generation of BQ,resulting in the obtained C-SiQD not responding to the CC.At the same time,the development of nanosensors can also avoid a variety of other possible interference.Under optimal conditions,the detection linear range for p-DHB is 0.01?M-50.0?M and the detection limit is 4.0 nM.The C-SiQDs-based dual signal sensor is suitable for the high selectivity and sensitivity of detecting trace amounts of p-DHB in various water samples.3.Good fluorescence stability,water solubility and biocompatibility were synthesizedbyhydrothermalreactionof?N-[3-?trimethoxysilyl?propyl]-ethylenediamine??DAMO?and catechol.Silicon quantum dots?SiQDs?.After the addition of hydrogen peroxide?H₂O₂?,the fluorescence of SiQDs is rapidly quenched by electron transfer.The method can detect H₂O₂ with high selectivity and high sensitivity.Under the optimal conditions,the linear detection range for H₂O₂ was 0.5?M-100.0?M,and the detection limit was0.2?M.The method was successfully applied to the detection of H₂O₂ in tap water and lake water.