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

Abstract

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 due to 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.

Antimicrobial and Cytotoxic Effect of Positively Charged Nanosilver-Coated Silk Sutures

“…In Figure b, the infrared spectroscopy analysis reveals the characteristic functional groups of the PEI polymer and P-AgNPs, including the stretching vibrations of the N–H amino group at 3265 cm –1 , CH 2 stretching vibrations at 2960 and 2832 cm –1 , NH 3+ species at 1655 cm –1 , NH 2 bending vibration at 1569 cm –1 , and CH 2 bending vibration at 1458 cm –1 . , The presence of these peaks was observed in both spectra; however, in the case of P-AgNPs, the intensity of PEI diminished, which corroborates that PEI was involved in the reduction and indicates successful coating on the surface of AgNPs, thereby helping in stabilization by electrostatic interactions, which prevents the aggregation of particles …”

“… 35 , 36 The presence of these peaks was observed in both spectra; however, in the case of P-AgNPs, the intensity of PEI diminished, which corroborates that PEI was involved in the reduction and indicates successful coating on the surface of AgNPs, thereby helping in stabilization by electrostatic interactions, which prevents the aggregation of particles. 37 …”