文献名： A magnetic relaxation switch sensor for determination of 17βEstradiol in milk and eggs based on aptamerfunctionalized Fe ₃ O ₄ @Au nanoparticles

作者 ： Xin Wang , Kaili Pei , Hanying Sun , Qi Wang

School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China

摘要：

BACKGROUND

A simple and rapid detection method for 17β-estradiol (E ₂ ) in complex food matrix is greatly desirable. A magnetic relaxation switch (MRS) sensor for detecting E ₂  based on the aptamer-functionalized gold-coated iron oxide (Fe ₃ O ₄ @Au) nanocomposite was designed in this study. Fe ₃ O ₄ @Au nanoparticles (NPs) played as a ‘switch’ between dispersed and aggregated states, while aptamer served as the recognition unit.

RESULTS

According to the sensing effect of monocomponent relaxation time ( T _2W ) for E ₂ , the volume ratio of aptamers to Fe ₃ O ₄ @Au, the sodium chloride (NaCl) concentration, the concentration of Fe ₃ O ₄ @Au@Apt, and reaction time were optimized to be 4:1, 0.03 mol L ^–1 , 4 μmol L ^–1  and 15 min, respectively. For the analysis of food sample, the E ₂  was quantified over a concentration range of 1 to 100 nmol L ^–1  with a detection limit of 7.6 nmol L ^–1  for milk samples, while a linearity range of 20 to 100 nmol L ^–1  and a detection limit of 8.57 nmol L ^–1  for egg samples.

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