Aptamer–Gold(III) Complex Nanoparticles: A New Way to Detect Cu, Zn SOD Glycoprotein

Abstract

Aptamers are small biomolecules composed of 20–100 nucleotides that recognize target molecules in three-dimensional structures. These natural targeting molecules have attracted interest in the biomedical field as biomarkers for cancer diagnostics. In this study, we investigated the interaction of a characteristic aptamer with its target protein, Cu, Zn superoxide dismutase (SOD 4), on a gold nanoparticle (AuNP) surface under experimental conditions. For this purpose, we applied two protocols to coat SOD 4 aptamer (APT) on the nanoparticle surface: carbodiimide chemistry (EDC/NHS) (Method ON) and a complexation methodology (Method IN). The nano-aptamer’s interactions with SOD 4 were detected by UV–vis absorption and Raman spectroscopy in a range of protein concentrations (from 1 μM to 50 nM). We believe that the interaction is heavily dependent on the nature of the biomarker (SOD 4) and also on the steric arrangement of the aptamer on the gold nanoparticle surface. The lowest detectable concentration (limit of detection, LOD) was about 2 nM for APT IN PEG-AuNPs and 8 nM for APT ON PEG-AuNPs. For the first time, we demonstrated a very sensitive detection of SOD 4 in the nanomolar concentration range with new ways of biosensor synthesis (APT IN and ON), providing a very strong tool to understand the effect of aptamer conformation to detect SOD 4.

Flavin-adenine-dinucleotide gold complex nanoparticles: chemical modeling design, physico-chemical assessment and perspectives in nanomedicine

“…30 c In the last few years, Spadavecchia et al developed two methods of synthesis, in which the first method consists of conjugating biomolecules (protein, antibody, peptides, and aptamers) onto pegylated gold nanoparticles (PEG-AuNPs) by carbodiimide chemistry (method ON). 31 …”

Biomolecular Corona Associated with Nanostructures: The Potentially Disruptive Role of Raman Microscopy

“…The effect of grafting method on the interaction between aptamer and SOD 4 glycoprotein [208] Nanoparticle-biomolecule interactions Raman spectroscopy ATP-TiO 2 NPs ATP-Fe content TiO 2 NPs Understanding the effect of Fe content on the interaction between TiO 2 NPs and ATP [209] BC studies SERS Endolysosome-AuNPs Isolated cytoplasm-AuNPs BSA-AuNPs Trypsin-AuNPs Trypsinized BSA-AuNPs Effect of active processing on intracellular BC and the corresponding protein-NP interactions [215] Raman imaging SRS microscopy Visualization of specific molecules, NPs, or drugs Enhancement in specific Raman signal of biomolecules, NPs, and/or Raman active tags for imaging purposes [194,196,193]…”

“…These were used to calculate the LODs and were found to be 8 × 10 −9 and 2 × 10 −9 m, respectively. [208] The study of Barkhade et al is another example of using Raman spectroscopy to investigate the interaction of NPs with biomolecules at the nano-biointerface. Titanium dioxide NPs (TiO 2 NPs) were selected, as they are widely used in daily products such as pharmaceuticals, papers, textiles, plastics, and cosmetics.…”

“…These were used to calculate the LODs and were found to be 8 × 10 −9 and 2 × 10 −9 m , respectively. [ 208 ]…”

Enzyme-Free Multiplex Detection of Foodborne Pathogens Using Au Nanoparticles-Decorated Multiwalled Carbon Nanotubes

“…The development of nanotechnology led to the generation of different nanomaterials and nanocomposites, which enabled improvements in sensitive and specific detection of pathogens. Among them, carbon-based nanomaterials (e.g., nanotubes, MWCNT, graphene, C-dots), , metallic , and magnetic nanoparticles (NPs), and quantum dots , have been largely employed in the area of biosensing, bioimaging, therapy, and pathogen detection. , Conversely, metallic NPs have been widely used for the conjugation of biomolecules and anticancer drugs . Interestingly, NP-decorated MWCNTs have been widely used for the detection of toxic ions and pathogens. , …”