Rudewicz-Kowalczyk Daria, Grabowska Iwona
Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland.
Sensors (Basel). 2021 Nov 20;21(22):7733. doi: 10.3390/s21227733.
An elevated level of low density lipoprotein (LDL) can lead to the cardiovascular system-related diseases, such as atherosclerosis and others. Therefore, fast, simple, and accurate methods for LDL detection are very desirable. In this work, the parameters characterizing the electrochemical immuno-and aptasensor for detection of LDL have been compared for the first time. An immunosensor has been designed, for which the anti-apolipoprotein B-100 antibody was covalently attached to 4-aminothiophenol (4-ATP) on the surface of the gold electrode. In the case of an aptasensor, the gold electrode was modified in a mixture of ssDNA aptamer specific for LDL modified with -SH group and 6-mercaptohexanol. Square-wave voltammetry has been used for detection of LDL in PBS containing redox active marker, [Fe(CN)]. Our results show the linear dependence of [Fe(CN)] redox signal changes on LDL concentration for both biosensors, in the range from 0.01 ng/mL to 1.0 ng/mL. The limit of detection was 0.31 and 0.25 ng/mL, for immuno- and aptasensor, respectively. Whereas slightly better selectivity toward human serum albumin (HSA), high density lipoprotein (HDL), and malondialdehyde modified low density lipoprotein (MDA-LDL) has been observed for aptasensor. Moreover, the other components of human blood serum samples did not influence aptasensor sensitivity.
低密度脂蛋白（LDL）水平升高会导致心血管系统相关疾病，如动脉粥样硬化等。因此，非常需要快速、简便且准确的LDL检测方法。在这项工作中，首次比较了用于检测LDL的电化学免疫传感器和适配体传感器的表征参数。设计了一种免疫传感器，将抗载脂蛋白B - 100抗体共价连接到金电极表面的4 - 氨基硫酚（4 - ATP）上。对于适配体传感器，金电极在用 - SH基团修饰的对LDL具有特异性的单链DNA适配体和6 - 巯基己醇的混合物中进行修饰。采用方波伏安法在含有氧化还原活性标记物[Fe(CN)]的磷酸盐缓冲液（PBS）中检测LDL。我们的结果表明，两种生物传感器的[Fe(CN)]氧化还原信号变化与LDL浓度在0.01 ng/mL至1.0 ng/mL范围内呈线性相关。免疫传感器和适配体传感器的检测限分别为0.31和0.25 ng/mL。然而，适配体传感器对人血清白蛋白（HSA）、高密度脂蛋白（HDL）和丙二醛修饰的低密度脂蛋白（MDA - LDL）具有稍好的选择性。此外，人血清样本中的其他成分不影响适配体传感器的灵敏度。
