Electrochemical Studies on the Binding of Antibody—Aptamer Hybrid Receptor Layers to HER2 Protein

Abstract

One of the possibilities of early detection of cancer disease is the analysis of the presence of protein biomarkers. Herein, we present the studies on the hybrid antibody—aptamer receptor layers for electrochemical detection of HER2 protein that is known as a biomarker of e.g. breast cancer. The application of MB-labelled aptamer did not allow to evidence the interaction with HER2 protein. Moreover, the use of unlabelled aptamer as a capture element and polyclonal antibody as a reporter probe did not show a dependence of current signal change vs HER2 protein concentration as well. On the contrary, the application of monoclonal antibody as a capture probe and aptamer labelled at 3′ end with MB as reporter probe enabled the determination of HER2 within 0.01–10 ng·ml−1 concentration range. The elaborated affinity assay also showed good selectivity towards HER2 biomarker and was used for HER2 determination in spiked serum sample.

Aptasensors versus immunosensors—Which will prevail?

“…Interestingly, for the aptamer-immobilized surface, the sandwich format with an antibody did not result in LOD improvement, while for the antibody-immobilized surface, the sandwich format with the aptamer resulted in a ten-fold improvement in the LOD. Marta et al investigated both sandwich formats for electrochemical biosensor for the detection of the Human Epidermal growth factor Receptor 2 (HER2) biomarker [170]. Although the aptamer immobilization on the gold electrode was simpler, its use as the capture element and the antibody as the reporter did not result in a reliable signal.…”

“…While low concentrations of the protein were not detected by the aptasensor (Figure 4A ), the subsequent introduction of an (unlabeled) IgG probe, which binds to the aptamer‐immobilized target, improved the LOD of the aptasensor by three‐fold. Alternatively, the aptamer can be employed as the reporter probe [ 153 , 166 , 168 , 170 ], where the oligonucleotide nature of the aptamers allows for distinctive amplification strategies (as described in Section 3.2 ). A popular biosensing configuration involves immobilization of a capture antibody on the transducing element (such as an electrode); the aptamer binds to the captured analyte and induces a cascade of subsequent reactions to allow sensitive detection [ 150 ].…”

“…Marta et al. investigated both sandwich formats for electrochemical biosensor for the detection of the Human Epidermal growth factor Receptor 2 (HER2) biomarker [ 170 ]. Although the aptamer immobilization on the gold electrode was simpler, its use as the capture element and the antibody as the reporter did not result in a reliable signal.…”

Microswimmer-Assisted Dual-Signal Sensor for Multiple Targets in Whole Blood

“…8,9 HER2 belongs to the growth factor receptor family (EGFR or ErbB) and is overexpressed in various epithelial-derived tumors, including breast cancer. 10,11 ER is a protein present in mammary epithelial cells that binds specifically to estrogen, forming a hormone−receptor complex that exerts biological effects when it enters the nucleus. 12,13 The interaction between ER and HER2 affects the effectiveness of HER2-targeted therapies.…”

“…Breast cancer is one of the most common malignant tumors in women. , Analyzing biomarkers in blood or cancer cells is a key method for early diagnosis. , Although diagnosis and treatment technologies for breast cancer have rapidly advanced, treatment failure and tumor recurrence remain major causes of death in breast cancer patients. − The growth, development, and cell proliferation of the mammary gland are influenced by risk factors such as estrogen receptor (ER), human epidermal growth factor receptor-2 (HER2), progesterone receptor, and Ki-67. , HER2 belongs to the growth factor receptor family (EGFR or ErbB) and is overexpressed in various epithelial-derived tumors, including breast cancer. , ER is a protein present in mammary epithelial cells that binds specifically to estrogen, forming a hormone–receptor complex that exerts biological effects when it enters the nucleus. , The interaction between ER and HER2 affects the effectiveness of HER2-targeted therapies . Clinical trial data demonstrate that simultaneous application of HER2-targeted therapy and ER-targeted therapy has a positive effect on breast cancer treatment .…”