恩诺沙星(ENR)被广泛用作合成的氟喹诺酮类抗生素,用于水生动物的疾病控制。在这项研究中,使用磁珠-SELEX方法筛选了ENR适体,并开发了氧化石墨烯荧光传感器来检测水产品中ENR的残留。首先,ENR通过酰胺化反应与氨基磁珠缀合,然后通过使用SELEX筛选方法逐步筛选对ENR显示高亲和力的适体序列。最后,经过10轮SELEX筛选,获得了6个高亲和力的候选适体。其中,ENR-Apt6是根据其二级结构特征选择的,高亲和力(Kd=35.08nM),和对ENR的高特异性。此外,使用氧化石墨烯和ENR-Apt6制备荧光传感器。结果表明,该传感器的线性范围可达600nM(R2=0.986),而其最佳线性范围为1-400nM(R2=0.991),最低检测限为14.72nM。所制备的传感器成功用于实际样品中ENR的检测,样品的回收率为83.676~114.992%,大部分样品的相对标准偏差<10%。
Enrofloxacin (ENR) is widely used as a synthetic fluoroquinolone antibiotic for disease control in aquatic animals. ENR aptamers were screened in this study using the magnetic bead-
SELEX method, and a graphene oxide fluorescent sensor was developed to detect the ENR residues in aquatic products. Firstly, ENR was conjugated to amino magnetic beads by amidation reaction, and then the aptamer sequences showing high affinity to ENR were screened step by step by using the
SELEX screening method. Finally, after 10 rounds of
SELEX screening, six candidate aptamers with high affinity were obtained. Among these, ENR-Apt 6 was selected based on its secondary structure features, high affinity (Kd = 35.08 nM), and high specificity to ENR. Furthermore, a fluorescent sensor was prepared using graphene oxide and ENR-Apt 6. The results showed that the linear range of the sensor could reach 600 nM (R2 = 0.986), while its optimal linear range was 1-400 nM (R2 = 0.991), with the lowest detection limit of 14.72 nM. The prepared sensor was successfully used for the detection of ENR in real samples, with a recovery range of 83.676-114.992% and a relative standard deviation < 10% for most of the samples.