Synthesis Of Gold Magnetic Nanoparticles And SERS Detection Of Tetrodotoxin

Tetrodotoxin toxicity were the strongest nonprotein toxoid in nature.Eating seafood containing 0.5 g tetrodotoxin can cause person death.Fatal accidents beacause of tetrodotoxin always happened every year.Tetrodotoxin safety problems become a top priority.Traditional methods of detection such as mouse biological method,High Performance Liquid Chromatography?HPLC?,Thin layer chromatography?TLC?,et al.They are time-consuming,laborious,suffering from poor repeatability and lack of specificity,and are not suitable for on-site rapid detection.Surface enhanced Raman Spectroscopy?SERS?is a kind of enhanced effect associated with rough surface,which has been widely used in surface science,analytical science and biological and other fields,is developing to a new method of rapid analysis.In this work,Fe₃O₄ nanoparticles were first modified with tetraethxoylsilane?TEOS?to form Fe₃O₄/Si O₂ nanoparticles,followed by the addition of 3-thiolpropyltriethxoysilane and3-aminopropyltriethxoysilane to introduce-NH2 and –SH to the surface of Fe₃O₄/SiO₂ nanoparticles.Au nanoparticles were further assembled on the surface of Fe₃O₄/Si O₂ via the electrostatic adsorption of-NH2 and the effect of Au-S bond to produce stable core-shell Fe₃O₄/SiO₂/Au gold magnetic nanoparticles.Using this structure as Raman active substrate to detect tetrodotoxin?TTX?rapidly finally.This Paper's contentment are as follows:?1?Preparation of gold nanoparticles with different sizes by changing the amount of sodium citrate,and investigate the influence of gold nanoparticles size on SERS enhancement effect.And determine the optimal average particle size of gold nanoparticles is 40 nm.The optimal condition for modification of magnetic nanoparticles is adding the same amount of APTES and MPTES.And the optimal condition for gold magnetic nanoparticles assembly is to use oscillation mode.In order to improve the stability of the gold magnetic nanoparticles,a small amount of TEOS is enough when coating silane layer which can fully cover the gold magnetic nanoparticles as well as maintain the SERS effect.?2?Using gold magnetic nanoparticles prepared under optimal condition as Raman active substrate.And at the same time labeled Fe₃O₄/SiO₂/Au/SiO₂-antiTTX and RhB-antiTTX,to indirectly rapid detecting of TTX,the detection limit can achieve 0.01?g/mL under the magnetic concentration.The single sample test time is less than 10 minutes.Detection linear range is 0.01 ?g/mL⁰.5 ?g/mL.Testing sample recovery rate is 84.54% 90.67%,relative standard deviation is 2.6% 11.1%.