Human ACE2 Peptide-Attached Plasmonic-Magnetic Heterostructure for Magnetic Separation, Surface Enhanced Raman Spectroscopy Identification, and Inhibition of Different Variants of SARS-CoV-2 Infections

Abstract

The emergence of Alpha, Beta, Gamma, Delta, and Omicron variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for several million deaths up to now. Because of the huge amount of vaccine escape mutations in the spike (S) protein for different variants, the design of material for combating SARS-CoV-2 is very important for our society. Herein, we report on the design of a human angiotensin converting enzyme 2 (ACE2) peptide-conjugated plasmonicmagnetic heterostructure, which has the capability for magnetic separation, identification via surface enhanced Raman spectroscopy (SERS), and inhibition of different variant SARS-CoV-2 infections. In this work, plasmonic-magnetic heterostructures were developed using the initial synthesis of polyethylenimine (PEI)-coated Fe 3 O 4 -based magnetic nanoparticles, and then gold nanoparticles (GNPs) were grown onto the surface of the magnetic nanoparticles. Experimental binding data between ACE2conjugated plasmonic-magnetic heterostructures and spike-receptor-binding domain (RBD) show that the Omicron variant has maximum binding ability, and it follows Alpha < Beta < Gamma < Delta < Omicron. Our finding shows that, due to the high magnetic moment (specific magnetization 40 emu/g), bioconjugated heterostructures are capable of effective magnetic separation of pseudotyped SARS-CoV-2 bearing the Delta variant spike from an infected artificial nasal mucus fluid sample using a simple bar magnet. Experimental data show that due to the formation of huge "hot spots" in the presence of SARS-CoV-2, Raman intensity for the 4-aminothiolphenol (4-ATP) Raman reporter was enhanced sharply, which has been used for the identification of separated virus. Theoretical calculations using finite-difference time-domain (FDTD) simulation indicate that, due to the "hot spots" formation, a six orders of magnitude Raman enhancement can be observed. A concentration-dependent inhibition efficiency investigation using a HEK293T-human cell line indicates that ACE2 peptide-conjugated plasmonic-magnetic heterostructures have the capability of complete inhibition of entry of different variants and original SARS-CoV-2 pseudovirions into host cells.

Application of Nanohybrid Substrates with Layer-by-Layer Self-Assembling Properties to High-Sensitivity Surface-Enhanced Raman Scattering Detection

“…In the fields of nanotechnology and materials science, organic/inorganic hybrids are regarded as some of the most important materials of the 21st century. − Many recent studies have explored the combination of metal nanoparticles with other organic/inorganic nanomaterials to improve SERS signals. , Common materials can be classified accordingly to form into sphere-like materials such as SiO 2 and Fe 2 O 3 , thread-like materials such as carbon nanotubes (CNTs) and polyvinyl alcohol (PVA) nanofibers, and sheet-like materials such as nanoclays and graphene . The use of nanohybrids increases the dispersibility of nanoparticles, as well as the electric field strength between metal particles.…”

Label-Free Analysis of Binding and Inhibition of SARS-Cov-19 Spike Proteins to ACE2 Receptor with ACE2-Derived Peptides by Surface Plasmon Resonance

“…The recent coronavirus disease (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected over 630 million individuals and has resulted in the death of over 6.6 million people as of November 2022, according to the World Health Organization (WHO) . While a great deal of effort has gone into developing new ways to treat and prevent the onset of COVID-19, − it is still affecting many people around the world, and it appears that it will continue to be present for the foreseeable future …”

Rapid Detection of SARS-CoV-2 Variants Using an Angiotensin-Converting Enzyme 2-Based Surface-Enhanced Raman Spectroscopy Sensor Enhanced by CoVari Deep Learning Algorithms

“…Therefore, such a change in ACE2 binding affinity due to mutations in the RBD amino acid sequence of S-protein makes ACE2-based capture detection advantageous for identifying SARS-CoV-2 variants . Though there are several reports on ACE2-based SERS sensors, ,− none of them take advantage of this. For example, Yang et al used ACE2-modified Au nanospike arrays and demonstrated a low limit of detection (LOD) of 80 copies/mL for SARS-CoV-2 in contaminated wastewater within 5 min .…”

“… 16 Zhang et al used ACE2-modified AgNR substrates to test the availability of COVID-19 from 23 water samples against bacteria. 17 Li et al 18 and Pramanik et al 19 used Fe 3 O 4 -based SERS substrates to collect and concentrate SARS-CoV-2 for SERS detection. Awada et al 20 and Yeh et al 21 recently focused on S-protein detection and achieved LODs of 1 fM and 1 fg/mL, respectively.…”