Bacterial detection using bacteriophages and gold nanorods by following time-dependent changes in Raman spectral signals

Moghtader, Farzaneh; Tomak, Aysel; Zareie, Hadi M.; Pi̇şki̇n, Erhan

doi:10.1080/21691401.2018.1452251

Cited by 14 publications

(10 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The detection of bacterial pathogens such as Pseudomonas fluorescens (P. fluorescens) is of significant interest both in life science and in environmental research, due to the fact that microbial contamination can result in significant health concern. − In this study, we have investigated the use of a microfabricated chip device in the detection of P. fluorescens and Pseudomonas putida (P.…”

Section: Resultsmentioning

confidence: 99%

Electric Field Tunability of Photoluminescence from a Hybrid Peptide–Plasmonic Metal Microfabricated Chip

Almohammed

Orhan

Daly

et al. 2021

JACS Au

View full text Add to dashboard Cite

Enhancement of fluorescence through the application of plasmonic metal nanostructures has gained substantial research attention due to the widespread use of fluorescence-based measurements and devices. Using a microfabricated plasmonic silver nanoparticle–organic semiconductor platform, we show experimentally the enhancement of fluorescence intensity achieved through electro-optical synergy. Fluorophores located sufficiently near silver nanoparticles are combined with diphenylalanine nanotubes (FFNTs) and subjected to a DC electric field. It is proposed that the enhancement of the fluorescence signal arises from the application of the electric field along the length of the FFNTs, which stimulates the pairing of low-energy electrons in the FFNTs with the silver nanoparticles, enabling charge transport across the metal–semiconductor template that enhances the electromagnetic field of the plasmonic nanoparticles. Many-body perturbation theory calculations indicate that, furthermore, the charging of silver may enhance its plasmonic performance intrinsically at particular wavelengths, through band-structure effects. These studies demonstrate for the first time that field-activated plasmonic hybrid platforms can improve fluorescence-based detection beyond using plasmonic nanoparticles alone. In order to widen the use of this hybrid platform, we have applied it to enhance fluorescence from bovine serum albumin and Pseudomonas fluorescens . Significant enhancement in fluorescence intensity was observed from both. The results obtained can provide a reference to be used in the development of biochemical sensors based on surface-enhanced fluorescence.

show abstract

Section: Resultsmentioning

confidence: 99%

Electric Field Tunability of Photoluminescence from a Hybrid Peptide–Plasmonic Metal Microfabricated Chip

Almohammed

Orhan

Daly

et al. 2021

JACS Au

View full text Add to dashboard Cite

show abstract

“…The synthesis of gold nanorods (AuNRs) is of considerable interest owing to their unique optical properties, which can be used for imaging, surface‐enhanced Raman spectroscopy (SERS), diagnostics, sensing, and biological applications . Murphy et al .…”

Section: Introductionmentioning

confidence: 99%

“…The synthesis of gold nanorods (AuNRs)i so fc onsiderable interest owing to their unique optical properties,w hich can be used for imaging, [1][2][3][4][5][6][7][8] surface-enhanced Raman spectroscopy (SERS), [9][10][11][12] diagnostics, [13][14][15] sensing, [16,17] and biologicala pplications. [18][19][20][21][22][23][24] Murphy et al [25] first reported the seed-mediated chemicals ynthesis of AuNRs.…”

Section: Introductionmentioning

confidence: 99%

Gram‐Scale Synthesis of Isolated Monodisperse Gold Nanorods

Khanal

Zubarev

2018

Chemistry A European J

View full text Add to dashboard Cite

Although gold nanorods (AuNRs) have strong potential applications in nanotechnology, plasmonics, and sensing, the scale‐up synthesis of isolated AuNRs in gram quantities remains a challenge. Nearly all previously reported methods produce aqueous solutions of cetyltrimethylammonium bromide (CTAB)‐coated AuNRs in milligram quantities with yields of approximately 20–30 % in terms of AuI to Au0 conversion. In addition, it is difficult to remove the CTAB bilayer from the surface of AuNRs and yet make them soluble and functionalized for further processing and chemical modification. This report describes the synthesis of monodisperse functionalized AuNRs (standard deviation, σ≈5 %) in gram quantities. Our approach involved increasing the concentration of HAuCl4⋅3 H2O in the growth solution to produce larger quantities of starting AuNRs and further reducing the remaining AuI ions onto the surface of AuNRs. The slow and controlled addition of ascorbic acid as a reducing agent continued the conversion of AuI into Au0 (through a disproportionation reaction) onto the surface of the nanorods, which maintained their uniform morphology without creating any unwanted impurities of various shapes. In addition, this approach significantly narrowed the size distribution owing to continuous growth of the partially grown AuNRs during the initial stage of the synthesis. To isolate a 1 g quantity of the AuNRs and to make them functionalized for further chemical reactions, a ligand‐exchange approach was utilized, in which the CTAB surfactant was replaced with 4‐mercaptophenol. The thiol group from 4‐mercaptophenol formed a covalent bond with the surface of the AuNRs, leaving free functional OH groups available for further chemical coupling reactions. For the ligand‐exchange process, a concentrated solution of 4‐mercaptophenol in tetrahydrofuran solution was introduced into the AuNRs solution. Pure AuNRs functionalized with 4‐mercaptophenol were isolated by dispersion and rinsing with an excess amount of THF, followed by centrifugation.

show abstract

“…4e, Supplementary Fig. 25) [55,[60][61][62][63][64][65][66][67][68][69][70]. We specifically note that peaks at 732.5 and 1330 cm -1 from our S. epi -containing samples are attributed to purine ring-breathing modes [65] and the Adenine part of the flavin derivatives or glycosidic ring mode of polysaccharides [64]; peaks at 755 and 1450 cm -1 from our E. coli -containing samples are attributed to Tryptophan ring breathing [70] and CH 2 /CH 3 deformation of proteins and lipids [62]; and peaks at 482 and 1124 cm -1 from our RBC-containing samples are attributed to γ12 out of plane deformation of porphyrin, a main component of hemoglobin [67], and ν13 or ν42 valence [68].…”

Section: Multi-cellular Droplet Classification and Raman Feature Impo...mentioning

confidence: 99%

Combining acoustic bioprinting with AI-assisted Raman spectroscopy for high-throughput identification of bacteria in blood

Safir¹,

Vu²,

Tadesse³

et al. 2022

Preprint

View full text Add to dashboard Cite

The presence of pathogens in complex, multi-cellular samples such as blood, urine, mucus, and wastewater can serve as indicators of active infection, and their identification can impact how human and environmental health are treated [1][2][3][4][5][6][7]. Surface-enhanced Raman spectroscopy (SERS) and machine learning (ML) can distinguish multiple pathogen species and strains [8][9][10][11], but processing complex fluid samples to sensitively and specifically detect pathogens remains an outstanding challenge. Here, we develop an acoustic bioprinting platform to digitize samples into millions of droplets, each containing just a few cells, which are then identified with SERS and ML. As a proof of concept, we focus on bacterial bloodstream infections. We demonstrate ∼2pL droplet generation from solutions containing S. epidermidis, E. coli, and mouse red blood cells (RBCs) mixed with gold nanorods (GNRs) at 1 kHz ejection rates; use of parallel printing heads would enable processing of mL-volume samples in minutes [12]. Droplets printed with GNRs achieve spectral enhancements of up to 1500x compared to samples printed without GNRs. With this improved signal-to-noise, we train an ML model on droplets consisting of either pure cells with GNRs or mixed, multicellular species with GNRs, using scanning electron microscopy images as our ground truth. We achieve ≥99% classification accuracy of droplets printed from cellularly-pure samples, and ≥87% accuracy in droplets printed from mixtures of S. epidermidis, E. coli, and RBCs. We compute the feature importance at each wavenumber and confirm that the most significant spectral bands for classification correspond to biologically relevant Raman peaks within our cells. This combined acoustic droplet ejection, SERS and ML platform could enable clinical and industrial translation of SERS-based cellular identification. MainReliable detection and identification of microorganisms is crucial for medical diagnostics, environmental monitoring, food production and safety, biodefense, biomanufacturing, and pharmaceutical development. Such samples typically contain as few as 1-100 colony-forming units (CFU)/mL[13-15], necessitating the use of in vitro liquid culturing for pathogen detection. It is estimated that less than 2% of all bacteria can be readily cultured using current laboratory protocols, and even amongst that 2%, culturing can take hours to days depending on the species [16][17][18][19]. In the case of medical diagnostics, broad spectrum antibiotics are often administered while waiting for culture results, leading to an alarming rise in antibiotic resistant bacteria. Antimicrobial resistance currently leads to ∼700,000 deaths per year, and is predicted to become the leading cause of death by 2050 [20]. To combat these trends, it is crucial to develop methods to rapidly detect and identify bacteria in diverse, complex samples.Raman spectroscopy is a label-free, vibrational spectroscopic technique that has recently emerged as a promising platform for bacterial species

show abstract

Bacterial detection using bacteriophages and gold nanorods by following time-dependent changes in Raman spectral signals

Cited by 14 publications

References 47 publications

Electric Field Tunability of Photoluminescence from a Hybrid Peptide–Plasmonic Metal Microfabricated Chip

Electric Field Tunability of Photoluminescence from a Hybrid Peptide–Plasmonic Metal Microfabricated Chip

Gram‐Scale Synthesis of Isolated Monodisperse Gold Nanorods

Combining acoustic bioprinting with AI-assisted Raman spectroscopy for high-throughput identification of bacteria in blood

Contact Info

Product

Resources

About