Gold nanoprobe-based non-crosslinking hybridization for molecular diagnostics

Abstract

Non-crosslinking (NCL) approaches using DNA-modified gold nanoparticles for molecular detection constitute powerful tools with potential implications in clinical diagnostics and tailored medicine. From detection of pathogenic agents to identification of specific point mutations associated with health conditions, these methods have shown remarkable versatility and simplicity. Herein, the NCL hybridization assay is broken down to the fundamentals behind its assembly and detection principle. Gold nanoparticle synthesis and derivatization is addressed, emphasizing optimal size homogeneity and conditions for maximum surface coverage, with direct implications in downstream detection. The detection principle is discussed and the advantages and drawbacks of different NCL approaches are discussed. Finally, NCL-based applications for molecular detection of clinically relevant loci and potential integration into more complex biosensing platforms, projecting miniaturization and portability are addressed.

Keywords:

• biodetection
• DNA
• gold nanoparticles
• molecular diagnostics
• nanodiagnostics
• nanoprobes
• non-crosslinking
• SNPs

Financial & competing interests disclosure

This work was supported by the Portuguese Foundation for Science and Technology (FCT-MEC), grant numbers PTDC/BBB-NAN/1812/2012 and SFRH/BD/87836/2012 to M Cordeiro; and SFRH/BD/52211/2013 to R Vinhas. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Key issues

• Gold nanoparticles properties for diagnostics.

• Nanodiagnostics options based on gold nanoparticles are alone or functionalized.

• High surface-to-volume ratio enables several capture/recognition elements to be grafted onto surface and enhances detection.

• Gold nanoprobe increases the sensitivity in DNA/RNA characterization, allowing for critical reduction of costs.

• Development of simple and cost-effective point-of-care platforms without the need for specialized technicians.

• Translation to the clinics is awaiting validation.

• Gold nanoparticle-based diagnostics is compared to gold standard – PCR amplification of DNA biomarkers – but is suitable for RNA analysis (gene expression assays; miRNA detection) without the need for retrotranscription, which surpasses current trends in RNA assays.

• Real-time monitoring – effective diagnostics at point of care.

Notes