2 research outputs found
Magnetism-Resolved Separation and Fluorescence Quantification for Near-Simultaneous Detection of Multiple Pathogens
In the modern era
of molecular evidence-based medicine and advanced
biomedical technologies, the rapid, sensitive and specific assay of
multiple pathogens is critical to, but largely absent from, clinical
practice. Therefore, to improve the current ordinary separation and
collection method, we report herein a strategy of magnetism-resolved
separation and fluorescence quantification for near-simultaneous detection
of multiple pathogens, followed by the direct antimicrobial susceptibility
testing (AST). To accomplish this strategy, we utilized aptamer-modified
fluorescent-magnetic multifunctional nanoprobes (apt-FMNPs). FMNPs
with intriguing different magnetic responses and excellent fluorescence
quality were first self-assembled based on metal coordination interaction
using (3-mercaptopropyl) trimethoxysilane, magnetic γ-Fe<sub>2</sub>O<sub>3</sub>, and fluorescent quantum dots as matrix components.
Then, aptamers, which specific to target pathogens of <i>Escherichia
coli O157:H7</i> (<i>E. coli</i>) and <i>Salmonella
typhimurium</i> (<i>S. typ</i>), were conjugated with
FMNPs to yield apt-FMNPs nanoprobes for multiple pathogens assay.
Based on the discrepant magnetic response of pathogen@nanoprobes complex
under the identical external magnetic field, the model bacteria were
fished out by magnetic adsorption at different time points and subjected
to fluorescence quantification with good linear ranges and detection
limits within 1h. Multiple pathogens spiked in real samples were also
effectively detected by the apt-FMNPs and sequentially fished out
for AST assay, which showed similar results to that for pure pathogens.
The apt-FMNPs-based strategy of near-simultaneous detection of multiple
pathogens shows promise for the potential application in the diagnosis
and treatment of pathogen-related infectious diseases
Dual-Recognition Förster Resonance Energy Transfer Based Platform for One-Step Sensitive Detection of Pathogenic Bacteria Using Fluorescent Vancomycin–Gold Nanoclusters and Aptamer–Gold Nanoparticles
The
effective monitoring, identification, and quantification of
pathogenic bacteria is essential for addressing serious public health
issues. In this study, we present a universal and facile one-step
strategy for sensitive and selective detection of pathogenic bacteria
using a dual-molecular affinity-based Förster (fluorescence)
resonance energy transfer (FRET) platform based on the recognition
of bacterial cell walls by antibiotic and aptamer molecules, respectively.
As a proof of concept, Vancomycin (Van) and a nucleic acid aptamer
were employed in a model dual-recognition scheme for detecting Staphylococcus aureus (Staph. aureus). Within 30 min, by using Van-functionalized gold nanoclusters and
aptamer-modified gold nanoparticles as the energy donor and acceptor,
respectively, the FRET signal shows a linear variation with the concentration
of Staph. aureus in the range from
20 to 10<sup>8</sup> cfu/mL with a detection limit of 10 cfu/mL. Other
nontarget bacteria showed negative results, demonstrating the good
specificity of the approach. When employed to assay Staph. aureus in real samples, the dual-recognition
FRET strategy showed recoveries from 99.00% to the 109.75% with relative
standard derivations (RSDs) less than 4%. This establishes a universal
detection platform for sensitive, specific, and simple pathogenic
bacteria detection, which could have great impact in the fields of
food/public safety monitoring and infectious disease diagnosis