Studies on the Affinity‐based Biosensors for Electrochemical Detection of HER2 Cancer Biomarker

Abstract

As cancer diseases are the second main cause of death it is necessary to elaborate fast and efficient early diagnosis methods for their detection. One of the possibilities is the analysis of protein biomarkers, which abnormal concentration in physiological fluids might be an indication of cancer disease progression. Herein, we present the studies on the development of affinity‐based biosensors for electrochemical detection of HER2 protein, which is a common biomarker of breast cancer. The main objective was to verify the possibility of fabrication of HER2‐specific hybrid aptamer‐polyclonal antibody and antibody‐based sandwich sensing layer on gold electrode surface. The effectiveness of each electrode modification step was confirmed using voltammetric and impedimetric techniques in the presence of ferri/ferrocyanide redox couple. It was observed that hybrid construct was unlikely to be formed on the gold electrode due to a higher affinity of secondary polyclonal antibody towards target protein, which resulted in the separation of HER2‐antibody complex from the electrode surface. On the contrary, an antibody‐based sandwich receptor layer allowed for protein discrimination in the range from 1 to 100 ng mL−1 by the application of TMB/H2O2 system and chronoamperometry detection technique. Though, the occurrence of interactions between interfering proteins and antibody‐based layer was noted, it led to at least two times smaller current responses than for HER2 protein.

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

“…Antibody-HER2-MB-labelled aptamer.-The possibility of formation of a stable antibody-based receptor layer for HER2 detection was previously shown in our group, 37 however such a monolayer did not allow for HER2 determination within a 1-100 ng•ml −1 concentration range. Therefore we applied a secondary antibody that was further conjugated with HRP enzyme, which catalyzed the oxidation of TMB substrate that was analyzed using amperometry technique.…”

“…36 Herein, we present the electrochemical studies on the interaction of affinity-based receptor layers with HER2 protein. It is a direct continuation of our previous research presented in 37 where we focused on the development of antibody sandwich layer for the analysis of HER2 biomarker. Firstly, we tested a hybrid construct consisting of antibodies and aptamer specific for HER2 biomarker that served either as a capture or reporter element (Schemes 1a and 1b).…”

“…However, further incubation of electrode with HER2 protein and polyclonal antibody did not cause the creation of a stable construct, as was shown in our previous studies. 37 This was attributed to the stronger interaction between HER2 protein and antibody that led to the separation of antibody-HER2 biomarker complex from the electrode surface. Nevertheless, we assumed that higher concentration of HER2 could contribute to the increase of Fe(CN) 6 3−/4− current because of its better access to the electrode surface caused by detachment of higher number of HER2-antibody complexes from the surface.…”

Biosensors Made of Synthetic Functional Nucleic Acids Toward Better Human Health

“…Of these papers, about half focused on human epidermal growth factor receptor 2 (HER2; Table ). − Biosensors were also developed for several other breast cancer biomarkers (or general cancer biomarkers assessed in breast cancer cells), which include miR-16 in MCF-7 cells (LOD, 16 fM), miR-21 (LOD, 0.1 fM), anterior gradient protein 2 homologue, extracellular vesicles, nucleolin (LODs, 6–8 cells/mL), ,,, CD44, platelet derived growth factor receptor beta, CA15-3 (LOD, 0.11 U/mL), and mucin 1 (LODs, 0.031 fM, 25 cells/mL, 0.25 pM, and 3.0 × 10 5 particles/μL). ,− …”

Ag nanorod@PEI-Ag nanohybrid as an excellent signal label for sensitive and rapid detection of serum HER2

“…For example, the biopsy is highly invasive and allows only a small part of a tissue to be analyzed. MRI and mammography also have disadvantages, such as the requirement for sophisticated equipment and inducing radiation doses in sensitive tissue (breast) 7 , 8 . One solution is the analysis of cancer biomarkers found in physiological fluids such as blood 9 – 12 .…”