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

Sep 24, 2026

Accurate detection of HER2, a critical breast cancer biomarker, enables earlier therapeutic decision-making and can reduce mortality for patients with HER2-overexpressing tumors. The study introduces a fast electrochemical approach using an Ag nanorod@polyethylenimine-Ag (Ag NR@PEI-Ag) nanohybrid label that combines silver electroactivity with the PEI high-surface-area contribution to amplify the detection signal. An HER2 aptamer is immobilized on a gold electrode, serum is exposed to form an aptamer-HER2 complex, and the electrochemical current from the Ag/AgCl reaction is measured. The aptasensor shows a broad linear range (10^-12 to 10^-7 g), a detection limit of 10 pg, and ~30 min total assay time.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages11

Reading Time28 min

AccessFree to download

Background

Importance of HER2 and early detection

Conventional diagnostic methods and limitations

Biomarkers and aptamer-based biosensing

Method

Ag NR@PEI-Ag nanohybrid as electrochemical label

Aptamer immobilization and detection mechanism

Performance

Linear range, LOD, and assay time

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN Ag nanorod@PEI‑Ag nanohybrid as an excellent signal label for sensitive and rapid detection of serum HER2 Fatemeh Hakimian & Mohammad Mazloum‑Ardakani * The accurate detection of Human epidermal growth factor receptor‑2 (HER2) as a critical breast cancer biomarker can be essential for the early selection of therapeutic approaches. HER2 is a prominent component of a signaling network. Overexpression of the HER2 protein due to amplification of its gene leads to the development of an aggressive subtype of breast cancer. Patients with tumors that overexpress HER2 are eligible for treatment that significantly reduces mortality rates. Herein, we present a fast and simple method for detecting serum HER2. A new electrochemical label has been developed using charged Ag nanorod@ polyethylenimine‑Ag (Ag NR@ PEI‑Ag) nanohybrid. The synthesized Ag NR@PEI‑Ag nanohybrid simultaneously has the electroactive property of silver and the large surface area of the PEI, which results in the enhancement of the detection signal. So, using Ag NR@PEI‑Ag nanohybrid as the electrochemical label, a simple, fast, and sensitive electrochemical biosensor was designed to detect HER2. This way, after immobilizing HER2 aptamer on the Au electrode surface, HER2 or human serum was exposed to the aptamer. Then, the positively charged Ag NR@PEI‑Ag nanohybrid was adsorbed onto the negatively charged aptamer‑HER2 complex, and the current that was produced dueto the Ag/AgCl reaction was measured as the electrochemical signal. The aptasensor shows a broad linear response from 10–12 to 10–7 g, a low detection limit (LOD) of 10 pg, and a total assay time of ~ 30 min. According to the statistics, in 2020, 2.3 million women worldwide were diagnosed with breast cancer, and unfortunately, 685,000 people died1. Late screening is one of the leading causes of this deadly disease2. Early detection of cancer and effective treatment planning can significantly increase survival rates. In this regard, there are various diagnostic methods for breast cancer detection, including biopsy3, breast magnetic resonance imaging (MRI)4, and mammography5,6. Although these methods are sensitive, they have some disadvantages. 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 blood9–12. The primary breast cancer-related protein biomarkers for non-invasive clinical tests are the Human Epidermal growth factor Receptor 2 (HER2 or ErbB2), Carcinoembryonic Antigen (CEA), and Cancer Antigen 15–3 (CA15- 3)13–15. HER2, as a critical prognostic indicator16, is overexpressed in 20 to 30% of breast cancers known as HER2-positive breast cancers17. HER2 stimulates the breast cancer cells to grow and spread more aggressively18. Sensitive detection of HER2 in serum samples is clinically essential for early awareness and breast cancer treatment19. Atthe moment, diagnostic tests of HER2 are mainly antibody-based methods like enzyme-linked immunosorbent assay (ELISA)18 and electrochemical immunosensing20,21. Despite the advantages of these methods, their most significant drawback is that antibodies are expensive and challenging to modify10. Aptamers are short, single-stranded RNA or DNA molecules22 with an inexpensive and specific binding ability with a particular target, such as small molecules23, proteins24, and whole cells25. They are widely used to design biosensors because of their easy compatibility with various platforms26. Aptasensors are a class of biosensors that use a DNA or RNA aptamer as the biological recognition element27. Aptasensors can be classified based on their transducer types, such as electrochemical, optical,

FAQs

What detection method is proposed for serum HER2?

A fast and simple electrochemical biosensor uses an HER2 aptamer and an Ag NR@PEI-Ag nanohybrid label to amplify the electrochemical signal.

How does the Ag NR@PEI-Ag nanohybrid enhance the signal?

It provides both silver electroactive properties and a large surface area from PEI, increasing the detection signal strength.

What are the reported analytical performance metrics?

The aptasensor exhibits a linear response from 10^-12 to 10^-7 g, a detection limit (LOD) of 10 pg, and a total assay time of about 30 minutes.

Sep 24, 2026

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