title: Sensitive DNA detection and SNP discrimination using ultrabright SERS nanorattles and magnetic beads for malaria diagnostics.
abstract: One of the major obstacles to implement nucleic acid-based molecular diagnostics at the point-of-care (POC) and in resource-limited settings is the lack of sensitive and practical DNA detection methods that can be seamlessly integrated into portable platforms. Herein we present a sensitive yet simple DNA detection method using a surface-enhanced Raman scattering (SERS) nanoplatform: the ultrabright SERS nanorattle. The method, referred to as the nanorattle-based method, involves sandwich hybridization of magnetic beads that are loaded with capture probes, target sequences, and ultrabright SERS nanorattles that are loaded with reporter probes. Upon hybridization, a magnet was applied to concentrate the hybridization sandwiches at a detection spot for SERS measurements. The ultrabright SERS nanorattles, composed of a core and a shell with resonance Raman reporters loaded in the gap space between the core and the shell, serve as SERS tags for signal detection. Using this method, a specific DNA sequence of the malaria parasite Plasmodium falciparum could be detected with a detection limit of approximately 100 attomoles. Single nucleotide polymorphism (SNP) discrimination of wild type malaria DNA and mutant malaria DNA, which confers resistance to artemisinin drugs, was also demonstrated. These test models demonstrate the molecular diagnostic potential of the nanorattle-based method to both detect and genotype infectious pathogens. Furthermore, the method's simplicity makes it a suitable candidate for integration into portable platforms for POC and in resource-limited settings applications.
authors.affiliation: Fitzpatrick Institute for Photonics, Duke University, Durham, NC 27708, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
authors.forename: Hoan T
authors.initials: HT
authors.lastname: Ngo
authors.affiliation: Fitzpatrick Institute for Photonics, Duke University, Durham, NC 27708, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
authors.forename: Naveen
authors.initials: N
authors.lastname: Gandra
authors.affiliation: Fitzpatrick Institute for Photonics, Duke University, Durham, NC 27708, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Fales
authors.affiliation: Fitzpatrick Institute for Photonics, Duke University, Durham, NC 27708, USA; Department of Medicine & Duke Global Health Institute, Duke University, Durham, NC 27708, USA.
authors.forename: Steve M
authors.initials: SM
authors.lastname: Taylor
authors.affiliation: Fitzpatrick Institute for Photonics, Duke University, Durham, NC 27708, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA; Department of Chemistry, Duke University, Durham, NC 27708, USA. Electronic address: tuan.vodinh@duke.edu.
authors.forename: Tuan
authors.initials: T
authors.lastname: Vo-Dinh
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D016054:DNA, Protozoan / Q000032:analysis* / Q000235:genetics; D004867:Equipment Design; D006801:Humans; D057230:Limit of Detection; D060526:Magnetic Fields; D059346:Magnets / Q000737:chemistry; D008288:Malaria / Q000175:diagnosis* / Q000469:parasitology; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D009693:Nucleic Acid Hybridization; D010963:Plasmodium falciparum / Q000235:genetics* / Q000302:isolation & purification*; D019095:Point-of-Care Systems; D020641:Polymorphism, Single Nucleotide; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*
chemical_list: D016054:DNA, Protozoan
keywords: Biosensing; DNA Detection; Molecular diagnostics; Nanoparticle; Point-of-care; SNP discrimination; Surface-enhanced Raman Scattering