“…Such enhancement in EF is a result of optimized Au precursor concentration and the size of MoS 2 nanosheets. The EF calculated here through size-selection of MoS 2 nanosheets is in par with previously reported protocols, although to note that it is achieved via an all solution route without the need for demanding synthetic conditions or chemicals ( Chen et al., 2020 ; Lv et al., 2020 ; Su et al., 2014 ; Tegegne et al., 2020 ). Figure 3 Au-decorated MoS 2 nanosheets as SERS substrates (A and B) (A) SERS spectra of methylene blue molecule (inset) on substrates of size-selected MoS 2 nanosheets reacted with different amounts of HAuCl 4 , and the (B) calculated enhancement factors of the respective SERS substrates.…”
“…Such enhancement in EF is a result of optimized Au precursor concentration and the size of MoS 2 nanosheets. The EF calculated here through size-selection of MoS 2 nanosheets is in par with previously reported protocols, although to note that it is achieved via an all solution route without the need for demanding synthetic conditions or chemicals ( Chen et al., 2020 ; Lv et al., 2020 ; Su et al., 2014 ; Tegegne et al., 2020 ). Figure 3 Au-decorated MoS 2 nanosheets as SERS substrates (A and B) (A) SERS spectra of methylene blue molecule (inset) on substrates of size-selected MoS 2 nanosheets reacted with different amounts of HAuCl 4 , and the (B) calculated enhancement factors of the respective SERS substrates.…”
“…In order to reveal the specific role played by MoS 2 in the SERS immunosensor, we compared its analytical performance with that of a traditional ELISA surface based on polystyrene in the absence of MoS 2 but using the same sandwich immunoassay protocol. It is worth noting that both sensors involve a similar practicality and rapidity, around 3 h, which is comparable to similar SERS biosensors Figure summarizes the sensitivity of the immunosensors at different AFP concentrations (1.0 to 1000.0 pg mL –1 ).…”
Section: Results
and Discussionmentioning
confidence: 54%
“…The choice of Au@AgNCs was motivated by their SERS-enhancing efficiency, − so that both the localized surface plasma resonance band of Au@AgNCs and the absorption band of R6G are resonant with the 532 nm laser (Figure S4). Indeed, Hwang et al have recently developed a similar ultrasensitive SERS system based on the AgNCs/MoS 2 platform that is able to detect R6G under 532 nm excitation . With this configuration, the developed SERS immunosensor presents several advantages: (i) direct anchoring of mAb on MoS 2 with no need for linker molecules such as mercaptobenzoic acid or thiolated-PEG, (ii) avoiding the use of metal nanostructure-based SERS tags and their potential degradation by oxidation of the metal (Ag in particular) during the functionalization step. , …”
The detection of cancer biomarkers at an early stage of tumor development
is vital for effective diagnosis and treatment of cancer. Current
diagnostic tools can often detect cancer only when the biomarker levels
are already too high, so that the tumors have spread and treatments
are less effective. It is urgent therefore to develop highly sensitive
assays for the detection of such biomarkers at the lowest possible
concentration. In this context, we developed a sandwich immunoassay
based on surface-enhanced Raman scattering (SERS) for the ultrasensitive
detection of α-fetoprotein (AFP), which is typically present
in human serum as a biomarker indicative of early stages of hepatocellular
carcinoma. In the immunoassay design, molybdenum disulfide (MoS2) modified with a monoclonal antibody was used as a capture
probe for AFP. A secondary antibody linked to an SERS-encoded nanoparticle
was employed as the Raman signal reporter, that is, the transducer
for AFP detection. The sandwich immunocomplex “capture probe/target/SERS
tag” was deposited on a silicon wafer and decorated with silver-coated
gold nanocubes to increase the density of “hot spots”
on the surface of the immunosensor. The developed SERS immunosensor
exhibits a wide linear detection range (1 pg mL–1 to 10 ng mL–1) with a limit of detection as low
as 0.03 pg mL–1 toward AFP with good reproducibility
(RSD < 6%) and stability. These parameters demonstrate that the
proposed immunosensor has the potential to be used as an analytical
platform for the detection of early-stage cancer biomarkers in clinical
applications.
“…Compared with metal, MoS 2 possesses unique adsorption capacity, especially for some aromatic molecules, because the π bonds of MoS 2 interplay with those of aromatic molecules [73,79]. Furthermore, MoS 2 has good fluorescence quenching ability and can quench background fluorescence, which is conducive to detection and substrate stability at low concentration [26,80]. However, its electromagnetic enhancement is extremely weak, and chemical enhancement alone can hardly contribute significantly to sensitivity.…”
Section: Mos 2 Substratesmentioning
confidence: 99%
“…Some of these 2D semiconductor materials are emphasized for their high chemical stability, good biocompatibility and controllability during fabrication [22][23][24]. Among them, MoS2 emerges as one of the most promising materials as a new platform for SERS research owing to its extraordinary adsorption capacity and fluorescence quenching ability [25,26]. Moreover, MoS2 has its In this review, we begin by introducing the fundamentals of SERS, including two commonly accepted SERS mechanisms and MoS 2 -related SERS mechanisms.…”
Surface-enhanced Raman scattering (SERS), as an important tool for interface research, occupies a place in the field of molecular detection and analysis due to its extremely high detection sensitivity and fingerprint characteristics. Substantial efforts have been put into the improvement of the enhancement factor (EF) by way of modifying SERS substrates. Recently, MoS2 has emerged as one of the most promising substrates for SERS, which is also exploited as a complementary platform on the conventional metal SERS substrates to optimize the properties. In this minireview, the fundamentals of MoS2-related SERS are first explicated. Then, the synthesis, advances and applications of MoS2-based substrates are illustrated with special emphasis on their practical applications in food safety, biomedical sensing and environmental monitoring, together with the corresponding challenges. This review is expected to arouse broad interest in nonplasmonic MoS2-related materials along with their mechanisms, and to promote the development of SERS studies.
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