Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima 10, 10-748 Olsztyn, Poland.
Molecules. 2022 Aug 26;27(17):5492. doi: 10.3390/molecules27175492.
Low-density lipoprotein (LDL) is a cardiac biomarker identified in the pathology of cardiovascular disease (CVD). Typically, the level of LDL is calculated using the Friedewald relationship based on measured values of total cholesterol, high-density lipoproteins (HDL), and triglycerides. Unfortunately, this approach leads to some errors in calculation. Therefore, direct methods that can be used for fast and accurate detection of LDL are needed. The purpose of this study was to develop an electrochemical platform for the detection of LDL based on an antibody-ferrocene conjugate. An anti-apolipoprotein B-100 antibody labeled with ferrocene was covalently immobilized on the layer of 4-aminothiophenol (4-ATP) on the surface of gold electrodes. Upon interaction between LDL and the antibody-ferrocene conjugate, a decrease in the ferrocene redox signal registered by square wave voltammetry was observed, which depends linearly on the concentration from 0.01 ng/mL to 1.0 ng/mL. The obtained limit of detection was equal to 0.53 ng/mL. Moreover, the satisfied selectivity toward human serum albumin (HSA), HDL, and malondialdehyde-modified low-density lipoprotein (MDA-LDL) was observed. In addition, the acceptable recovery rates of LDL in human serum samples indicate the possible application of immunosensors presented in clinical diagnostics.
低密度脂蛋白（LDL）是心血管疾病（CVD）病理中的一种心脏生物标志物。通常，LDL 的水平是通过基于总胆固醇、高密度脂蛋白（HDL）和甘油三酯的测量值的 Friedewald 关系计算得出的。然而，这种方法会导致计算上的一些误差。因此，需要能够快速准确地检测 LDL 的直接方法。本研究旨在开发一种基于抗体-二茂铁结合物的用于检测 LDL 的电化学平台。用二茂铁标记的载脂蛋白 B-100 抗体通过共价键固定在金电极表面的 4-巯基苯胺（4-ATP）层上。当 LDL 与抗体-二茂铁结合物相互作用时，通过方波伏安法记录到二茂铁氧化还原信号的降低，该信号与浓度呈线性关系，范围从 0.01ng/mL 到 1.0ng/mL。获得的检测限等于 0.53ng/mL。此外，还观察到对人血清白蛋白（HSA）、HDL 和丙二醛修饰的低密度脂蛋白（MDA-LDL）具有令人满意的选择性。此外，在人血清样本中 LDL 的可接受回收率表明所提出的免疫传感器在临床诊断中的可能应用。
