| dc.description.abstract | Staphylococcus aureus (S. aureus) is the most prevalent cause of hospitalacquired infections and is regarded as one of the leading bacteria contributing to
foodborne diseases. Numerous techniques have been developed for S. aureus detection
and quantification. Nevertheless, the majority of these techniques often require laborious
sample preparation processes and take a long time. Thus, the development of a quick,
easy, and sensitive detection technique is very desirable. A colorimetric biosensor based
on catalytic gold nanoparticles was created to overcome these restrictions. In this study, a
colorimetric biosensor for fast detection of S. aureus based on catalytic gold
nanoparticles was developed, which is based on an RNA of bacteria, single-stranded
specific cleavage activity of Mung bean nuclease enzyme, and peroxidase-like activity of
AuNPs on TMB. Without the use of an analytical tool, it is possible to quantify the
response signals with the naked eye and determine the outcomes. The presence of target
RNA is implied by the fact that the DNA-RNA hybrid, once created, resists the cleavage
of the Mung bean nuclease enzyme and maintains its red color in the solution. When an
RNA target is not present, this prevents DNA-RNA hybridization from occurring, singlestranded DNA probes are vulnerable to enzymatic breakage by Mung bean nuclease,
which leaves the unprotected nanoparticles. Unprotected AuNPs may oxidize 3,3,5,5-
tetramethylbenzidine (TMB) and cause it to become blue in aqueous solutions by
catalyzing the reaction with H2O2. In short, the nanosensor simply changed color, when
the RNA non-target was present in the samples. The biosensor findings were visually
inspected and subjected to UV-Vis spectroscopic analysis. The specificity of the method
is demonstrated by the absence of false positive results. The naked eye detection limit of
this method is 107 CFU/ml. The total analysis time for this method is approximately two
and a half hours after RNA extraction. This sensing tool requires a minute to obtain the
results. This nanosensor platform, when compared to conventional techniques, could
offer a fresh approach and satisfy the pressing need to improve pathogenic bacterial
detection, which includes making it easy, affordable, rapid, and suitable for in situ
detection. | en_US |
