Octupolar Metastructures for a Highly Sensitive, Rapid, and Reproducible Phage-Based Detection of Bacterial Pathogens by Surface-Enhanced Raman Scattering

Abstract

The development of fast and ultrasensitive methods to detect bacterial pathogens at low concentrations is of high relevance for human and animal health care and diagnostics. In this context, surface-enhanced Raman scattering (SERS) offers the promise of a simplified, rapid, and high-sensitive detection of biomolecular interactions with several advantages over previous assay methodologies. In this work, we have conceived reproducible SERS nanosensors based on tailored multilayer octupolar nanostructures which can combine high enhancement factor and remarkable molecular selectivity. We show that coating novel multilayer octupolar metastructures with proper self-assembled monolayer (SAM) and immobilized phages can provide label-free analysis of pathogenic bacteria via SERS leading to a giant increase in SERS enhancement. The strong relative intensity changes of about 2100% at the maximum scattered SERS wavelength, induced by the Brucella bacterium captured, demonstrate the performance advantages of the bacteriophage sensing scheme. We performed measurements at the single-cell level thus allowing fast identification in less than an hour without any demanding sample preparation process. Our results based on designing well-controlled octupolar coupling platforms open up new opportunities toward the use of bacteriophages as recognition elements for the creation of SERS-based multifunctional biochips for rapid culture and label-free detection of bacteria.

Surface‐Enhanced Raman Scattering for Rapid Detection and Characterization of Antibiotic‐Resistant Bacteria

“…Rippa et al developed a Raman reporter‐bacteriophage recognition strategy on novel octupolar metastructures for detection of Brucella ( Figure a) . The intricate nanostructured arrays were realized with EBL, and are shown in Figure b.…”

“…The high density of sharp vertices confined the plasmon resonance, and increased the SERS sensitivity. Reproduced with permission . Copyright 2017, American Chemical Society.…”

Nanoparticles for Signaling in Biodiagnosis and Treatment of Infectious Diseases

“…A single nanohole in a metal layer is capable of supporting a LSP [ 45 ]. New technologies based on nanocavity-shaped photonic crystals with strong plasmonic signals have been developed with potential applications in bacterial detection [ 46 , 47 , 48 ].…”

“…These kinds of structures, combined with SERS, permit rapid and highly sensitive bacteriophage detection of pathogenic bacteria such as Brucella sp. [ 48 ].…”

Fluorescence-Free Biosensor Methods in Detection of Food Pathogens with a Special Focus on Listeria monocytogenes

“…Biosensors often rely on direct detection methods, such as surface enhanced raman scattering (SERS), electrochemical methods, lateral flow immuno-assays, and on applications of metal nanoparticles, quantum dots, and nanomaterials for surface modification [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Among the detection methods providing signal enhancements at low bacteria contamination, the electrochemical methods, in which signal amplification is achieved through enzymes and redox cycling, have been recently extensively reviewed [ 17 , 18 , 19 , 20 ].…”