Enhanced Electrochemical Detection for DNA Hybridization on Core-Shell Magnetic Silica Sphere Gold Nanoparticles.

In this work, we have reported a new electrochemical approach for detection of DNA hybridization-based core-shell magnetic silica sphere gold nanoparticles (MSS@AuNPs) coated on a gold electrode. The as-synthesized nanoparticles were synthesized in a three-step process and characterized by using ultraviolet-visible spectra, FTIR spectra, Raman spectra, a vibrating sample magnetometer, and X-ray diffraction techniques, respectively. Our results demonstrate that 51 nm MSS@AuNPs with 12 nm thickness of silica and 10 nm thickness of gold layer possess outstanding electron transport capabilities on gold electrodes, enabling the highly sensitive detection of complementary DNA targets at a remarkable limit of 0.47 ± 0.20 pM using differential pulse voltammetry (DPV). Furthermore, the amperometric detection sensitivity reached 0.27 ± 0.10 pM, highlighting the impressive performance of this biosensor. It can effectively differentiate between perfectly matched sequences (CT), mismatched sequences (MT), deleted sequences (DT), and noncomplementary targets (NT) with exceptional precision. The proposed sensor shows high robustness, reproducibility, and stability reinforcing its potential for future applications. This research not only advances the development of sophisticated diagnostic tools but also opens new pathways for innovative treatments in biomedical research.