Gold nanoparticles as a probe for prion determination via resonance light scattering method

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• Prion diseases pose significant diagnostic challenges.
• Existing detection methods for prion proteins often lack sensitivity or require complex procedures.

Purpose of the Study:

• To develop a novel, highly selective, and sensitive assay for detecting prion proteins.
• To utilize dihydrolipoic acid (DHLA) modified gold nanoparticles (AuNPs) as a probe for prion detection.

Main Methods:

• Gold nanoparticles (AuNPs) modified with dihydrolipoic acid (DHLA) were synthesized.
• The aggregation of DHLA-AuNPs in the presence of recombinant prion protein (rPrP) was investigated.
• Resonance light scattering (RLS) was employed to quantify AuNP aggregation and thus rPrP concentration.

Main Results:

• DHLA-modified AuNPs exhibited selective aggregation in the presence of rPrP.
• This aggregation led to a significant enhancement in RLS intensity, forming the basis of the assay.
• The assay demonstrated a wide linear detection range (2.0 × 10⁻¹⁰ to 2.0 × 10⁻⁸ mol L⁻¹) with a low detection limit (7 × 10⁻¹¹ mol L⁻¹).
• Excellent discrimination against interfering compounds was observed.
• The assay was successfully applied to detect rPrP in E. coli lysate, bovine serum, and human plasma.

Conclusions:

• A label-free, highly selective, and sensitive assay for prion protein detection has been established using DHLA-modified AuNPs.
• The assay leverages the phenomenon of selective AuNP aggregation and RLS enhancement.
• This method offers a promising alternative to conventional techniques, requiring no complex labeling or expensive instrumentation.