2 research outputs found
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
Dual Recognition Strategy for Specific and Sensitive Detection of Bacteria Using Aptamer-Coated Magnetic Beads and Antibiotic-Capped Gold Nanoclusters
Food poisoning and infectious diseases
caused by pathogenic bacteria
such as Staphylococcus aureus (SA) are serious public health concerns. A method
of specific, sensitive, and rapid detection of such bacteria is essential
and important. This study presents a strategy that combines aptamer
and antibiotic-based dual recognition units with magnetic enrichment
and fluorescent detection to achieve specific and sensitive quantification
of SA in authentic specimens and in
the presence of much higher concentrations of other bacteria. Aptamer-coated
magnetic beads (Apt-MB) were employed for specific capture of SA. Vancomycin-stabilized fluorescent gold nanoclusters
(AuNCs@Van) were prepared by a simple one-step process and used for
sensitive quantification of SA in the
range of 32–10<sup>8</sup> cfu/mL with the detection limit
of 16 cfu/mL via a fluorescence intensity measurement. And using this
strategy, about 70 cfu/mL of <i>SA</i> in complex samples
(containing 3 × 10<sup>8</sup> cfu/mL of other different contaminated
bacteria) could be successfully detected. In comparison to prior studies,
the developed strategy here not only simplifies the preparation procedure
of the fluorescent probes (AuNCs@Van) to a great extent but also could
sensitively quantify SA in the presence
of much higher concentrations of other bacteria directly with good
accuracy. Moreover, the aptamer and antibiotic used in this strategy
are much less expensive and widely available compared to common-used
antibodies, making it cost-effective. This general aptamer- and antibiotic-based
dual recognition strategy, combined with magnetic enrichment and fluorescent
detection of trace bacteria, shows great potential application in
monitoring bacterial food contamination and infectious diseases