scholarly journals Ag@ZIF-67 decorated cotton fabric as flexible, stable and sensitive SERS substrate for label-free detection of Phenol-soluble modulin

2021 ◽  
Author(s):  
Jiangtao Xu ◽  
Songmin Shang ◽  
Wei Gao ◽  
Ping Zeng ◽  
Shouxiang Kinor Jiang
Keyword(s):  
Cotton Fabric ◽  
Detection Sensitivity ◽  
Sers Substrate ◽  
Label Free ◽  
Zeolitic Imidazolate Frameworks ◽  
Practical Applications ◽  
Sampling Process ◽  
Label Free Detection ◽  
Clinical Diagnoses ◽  
Surface Enhanced Raman

Abstract Although strategies of compositing noble materials and Zeolitic imidazolate frameworks (ZIFs) have been used to enhance the performance of ZIF-based surface-enhanced Raman scattering (SERS) substrates, the enhancement process still remains unclear and the sampling process with powder-form substrates is challenging for practical applications. In this study, a flexible SERS substrate with silver (Ag) nanoparticle decorated ZIF-67 as the active materials and cotton fabric as the supporting framework is developed with a facile method in two steps. The proposed flexible SERS substrate not only can reduce difficulties during the sampling process, but also expands future applications for sampling towards irregular target substances. Meanwhile, the enhancement mechanism has been investigated by using Methylene Blue (MB) to probe the molecular interactions. The constructed SERS substrate shows the highest enhancement factor of 6.25×106 and an excellent detection sensitivity with a limitation of detection (LoD) of 10− 14 M/L. Because of its excellent performance in SERS tracing, the proposed SERS substrate shows exceptional ability in detecting and identifying phenol-soluble modulins and is considered to be a label-free approach that requires no adding markers/tags or antibodies. The proposed substrate expands the potential applications of SERS technology for rapid detection of bacterial toxins during clinical diagnoses and treatment.

scholarly journals Rapid label-free SERS detection of foodborne pathogenic bacteria based on hafnium ditelluride-Au nanocomposites

2020 ◽  
Vol 13 (05) ◽  
pp. 2041004 ◽  
Author(s):  
Yang Li ◽  
Yanxian Guo ◽  
Binggang Ye ◽  
Zhengfei Zhuang ◽  
Peilin Lan ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Limit Of Detection ◽  
Principal Component ◽  
High Sensitivity ◽  
Chemical Mechanism ◽  
Sers Substrate ◽  
Label Free ◽  
Label Free Detection ◽  
Surface Enhanced Raman ◽  
Foodborne Pathogenic Bacteria

Two-dimensional (2D) nanomaterials have captured an increasing attention in biophotonics owing to their excellent optical features. Herein, 2D hafnium ditelluride (HfTe[Formula: see text], a new member of transition metal tellurides, is exploited to support gold nanoparticles fabricating HfTe2-Au nanocomposites. The nanohybrids can serve as novel 2D surface-enhanced Raman scattering (SERS) substrate for the label-free detection of analyte with high sensitivity and reproducibility. Chemical mechanism originated from HfTe2 nanosheets and the electromagnetic enhancement induced by the hot spots on the nanohybrids may largely contribute to the superior SERS effect of HfTe2-Au nanocomposites. Finally, HfTe2-Au nanocomposites are utilized for the label-free SERS analysis of foodborne pathogenic bacteria, which realize the rapid and ultrasensitive Raman test of Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella with the limit of detection of 10 CFU/mL and the maximum Raman enhancement factor up to [Formula: see text]. Combined with principal component analysis, HfTe2-Au-based SERS analysis also completes the bacterial classification without extra treatment.

scholarly journals Magnetic Assembly Route to Construct Reproducible and Recyclable SERS Substrate

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Bingfang Zou ◽  
Chunyu Niu ◽  
Ming Ma ◽  
Lu Zhao ◽  
Yongqiang Wang
Keyword(s):  
Noble Metal ◽  
Reaction System ◽  
Practical Interest ◽  
Building Blocks ◽  
Detection Sensitivity ◽  
Sers Substrate ◽  
Magnetic Assembly ◽  
Surface Enhanced Raman ◽  
Signal Sensitivity ◽  
Uniform Array

AbstractThe fabrication of a uniform array film through assembly of colloidal building blocks is of practical interest for the integrated individual and collective functions. Here, a magnetic assembly route was put forward to organize monodisperse noble metal microspheres into a uniform array film for surface-enhanced Raman scattering (SERS) application, which demonstrated the integrated signal sensitivity of single noble metal microspheres and reproducibility of their assembled uniform array film. For this purpose, monodisperse multifunctional Fe3O4@SiO2@TiO2@Ag (FOSTA) colloidal microspheres as building blocks were successfully synthesized through a homemade ultrasonic-assisted reaction system. When used in SERS test, these multifunctional microspheres could firstly bind the analyte (R6G) from solution and then assembled into a uniform film under an external magnetic field, which exhibited high SERS detection sensitivity with good reproducibility. In addition, due to the TiO2 interlayer in FOSTA colloidal microspheres, the building blocks could be recycled and self cleaned through photocatalytic degradation of the adsorbed analyte for recycling SERS application.

scholarly journals Design of Inverted Nano-Cone Arrayed SERS Substrate for Rapid Detection of Pathogens

2021 ◽  
Vol 11 (17) ◽  
pp. 8067
Author(s):  
Zixun Jia ◽  
Sarah Asiri ◽  
Asma Elsharif ◽  
Widyan Alamoudi ◽  
Ebtesam Al-Suhaimi ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Rapid Detection ◽  
Close Contact ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Label Free ◽  
Surface Enhanced Raman ◽  
Order Of Magnitude ◽  
The Right ◽  
Pathogen Diagnosis

Rapid detection of bacteria is a very critical and important part of infectious disease treatment. Sepsis kills more than 25 percent of its victims, resulting in as many as half of all deaths in hospitals before identifying the pathogen for patients to get the right treatment. Raman spectroscopy is a promising candidate in pathogen diagnosis given its fast and label-free nature, only if the concentration of the pathogen is high enough to provide reasonable sensitivity. This work reports a new design of surface-enhanced Raman spectroscopy (SERS) substrate which will provide high enough sensitivity and fast and close contact of the target structure to the optical hot spots for immunomagnetic capturing-based bacteria-concentrating technique. The substrate uses inverted nanocone structure arrays made of transparent PDMS (Polydimethylsiloxane) to funnel the light from the bottom to the top of the cones where plasmonic gold nanorods are located. A high reflective and low loss layer is deposited on the outer surface of the cone. Given the geometry of cones, photons are multi-reflected by the outer layer and thus the number density of photons at hotspots increases by an order of magnitude, which could be high enough to detect immunomagnetically densified bacteria.

scholarly journals Application of Aluminum Hydroxide for Improvement of Label-Free SERS Detection of Some Cephalosporin Antibiotics in Urine

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 91 ◽  
Author(s):  
Natalia E. Markina ◽  
Alexey V. Markin
Keyword(s):  
Aluminum Hydroxide ◽  
Surface Enhanced Raman Spectroscopy ◽  
Negative Influence ◽  
Quantitative Detection ◽  
Therapeutic Drug ◽  
Excitation Wavelength ◽  
Sers Substrate ◽  
Label Free ◽  
Surface Enhanced Raman ◽  
Sers Detection

This report is dedicated to development of surface-enhanced Raman spectroscopy (SERS) based analysis protocol for detection of antibiotics in urine. The key step of the protocol is the pretreatment of urine before the detection to minimize background signal. The pretreatment includes extraction of intrinsic urine components using aluminum hydroxide gel (AHG) and further pH adjusting of the purified sample. The protocol was tested by detection of a single antibiotic in artificially spiked samples of real urine. Five antibiotics of cephalosporin class (cefazolin, cefoperazone, cefotaxime, ceftriaxone, and cefuroxime) were used for testing. SERS measurements were performed using a portable Raman spectrometer with 638 nm excitation wavelength and silver nanoparticles as SERS substrate. The calibration curves of four antibiotics (cefuroxime is the exception) cover the concentrations required for detection in patient’s urine during therapy (25/100‒500 μg/mL). Random error of the analysis (RSD < 20%) and limits of quantification (20‒90 μg/mL) for these antibiotics demonstrate the applicability of the protocol for reliable quantitative detection during therapeutic drug monitoring. The detection of cefuroxime using the protocol is not sensitive enough, allowing only for qualitative detection. Additionally, time stability and batch-to-batch reproducibility of AHG were studied and negative influence of the pretreatment protocol and its limitations were estimated and discussed.

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