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研究了电化学传感器对动物源性食品中红霉素残留的测定。采用电沉积法和共价吸附法将纳米金和壳聚糖/普鲁士蓝/石墨烯复合物修饰到电极表面,构建一种灵敏的电化学免疫传感器。对修饰的电化学传感器进行优化,选取100 ng/m L作为固定抗原的浓度,40 min作为培养时间。对不同浓度红霉素溶液进行检测,得到的线性范围为0.3~1000 mg/m L,检测限为0.15 ng/m L。采用罗红霉素作为干扰物检测电化学传感器的选择性;利用5根电极对同一浓度的红霉素溶液进行测定,其对标准偏差范围为3.8%~5.1%;单支电极连续5次在100 ng/m L的红霉素溶液中测定的标准偏差为4.6%;储存一周后的电化学传感器测定红霉素浓度的标准偏差为4.5%。通过对实际样品(猪肉)的加标测定,回收率范围为86.0%~103.1%。综上所述,该电化学传感器具有很好的选择性、重现性、稳定性和准确性,可以用于猪肉中红霉素残留的检测。
Electrochemical sensors were studied for the determination of erythromycin residues in animal-derived foods. Gold nanoparticles and chitosan / Prussian blue / graphene composite were modified onto the electrode surface by electrodeposition and covalent adsorption method to construct a sensitive electrochemical immunosensor. The modified electrochemical sensor was optimized. The concentration of 100 ng / mL was used as the fixed antigen, and the incubation time was 40 min. Different concentrations of erythromycin solution were detected, the linear range of 0.3 ~ 1000 mg / m L, the detection limit of 0.15 ng / m L. Using roxithromycin as an interfering substance to detect the selectivity of the electrochemical sensor; using 5 electrodes to measure the same concentration of erythromycin solution, the standard deviation ranged from 3.8% to 5.1% The standard deviation of the erythromycin solution of 100 ng / mL was 4.6%. After one week of storage, the standard deviation of erythromycin concentration was 4.5%. Through the spiked measurement of real samples (pork), the recoveries ranged from 86.0% to 103.1%. In summary, the electrochemical sensor has good selectivity, reproducibility, stability and accuracy, can be used for the detection of erythromycin residues in pork.