scholarly journals Identifying and detecting Entomopathogenic fungi using Surface-enhanced Raman spectroscopy / Identificação e detecção de fungos entomopatogênicos utilizando Superficie-enhanced Raman espalhamento

2021 ◽  
Vol 4 (4) ◽  
pp. 4833-4851
Author(s):  
Javier Christian Ramirez Perez ◽  
Tatiana Alves Dos Reis ◽  
Marcia de Almeida Rizzutto
Keyword(s):  
Raman Spectroscopy ◽  
Entomopathogenic Fungi ◽  
Insect Pests ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Spectrum ◽  
Natural Ecosystem ◽  
Fungal Entomopathogens ◽  
Short Period ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

In the natural ecosystem, fungal entomopathogens are the most efficient biocontrol agents against insect pests. In this study we offer an alternative for conventional fungal diagnostic, Surface-enhanced Raman spectroscopy (SERS) technique combine with principal component analysis (PCA) for detection and identification three entomopathogenic fungi, namely, IBCB 66 Beauveria bassiana, IBCB 130 Isaria fumosorosea, and IBCB 425 Metarhizium anisopliae. Using a simple preparation approach, highly active silver nanoparticles suitable for detecting complex biomolecules were produced for application in the SERS technique. Entomopathogens fungi produced highly enhanced and reproducible Raman signals based on their biochemical composition due to the high density of hot spots at the confluence of silver nano-aggregates, allowing the three entomopathogens species to be differentiated in the SERS spectrum fingerprint region, 550-1700 cm-1. The SERS method, along with PCA analysis, accounted for over 99 % of total variance and allowed for very high probability discrimination between the three entomopathogens, allowing taxonomic affiliation to be determined in a short period of time.  These findings suggest that the SERS methodology can be used to develop a new, fast, accurate, and cost-effective diagnostic method for fungal entomopathogens.

scholarly journals SERS study on myeloperoxidase and its immunocomplex: Identification of binding interactions

2010 ◽  
Vol 24 (3-4) ◽  
pp. 183-190
Author(s):  
Elisabeth S. Papazoglou ◽  
Sundar Babu ◽  
David R. Hansberry ◽  
Sakya Mohapatra ◽  
Chirag Patel
Keyword(s):  
Amino Acids ◽  
Raman Spectroscopy ◽  
Conformational Changes ◽  
Surface Enhanced Raman Spectroscopy ◽  
Biological Molecules ◽  
Sers Spectrum ◽  
Amino Acid Residues ◽  
Igg Antibodies ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Surface Enhanced Raman Spectroscopy (SERS) has demonstrated significant benefit in the identification of biological molecules. In this paper we have examined how to identify and differentiate the 150 kDa protein myeloperoxidase (MPO) from its corresponding antibody (Ab) and their immunocomplex through the use of SERS. The SERS signal of these biological molecules was enabled by 40 nm gold nanoparticles. The SERS spectra for both MPO and the Ab (an IgG molecule) demonstrated results consistent with previous published work on the Raman spectra of MPO and IgG antibodies. The immunocomplex SERS spectra showed peak shifts and intensity variations that could be attributed to conformational changes that occur during immunocomplex formation. Several key spectral areas have been identified which correspond to specific amino acids being shielded from undergoing resonance while new amino acid residues are made visible in the SERS spectrum of the immunocomplex and could be a result of conformational binding. These results indicate that SERS can be used to identify binding events and distinguish an immunocomplex from its individual components.

Potential-Averaged Surface-Enhanced Raman Spectroscopy

1996 ◽  
Vol 50 (12) ◽  
pp. 1569-1577 ◽  
Author(s):  
Z. Q. Tian ◽  
W. H. Li ◽  
B. W. Mao ◽  
S. Z. Zou ◽  
J. S. Gao
Keyword(s):  
Raman Spectroscopy ◽  
Active Sites ◽  
Single Channel ◽  
Pulse Height ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Spectrum ◽  
Surface Species ◽  
Electrode Potentials ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

This paper describes a novel technique called potential-averaged surface-enhanced Raman spectroscopy (PASERS) which has several advantages over SERS. A PASERS spectrum is acquired when the electrode is rapidly modulated between two potentials by applying a square-wave voltage. The potential-averaged SERS spectrum contains all the information on the surface species at the two modulated potentials, and each individual SERS spectrum can then be extracted by deconvolution. By properly choosing the two modulating potentials, one can obtain SERS spectra of surface species at electrode potentials where SERS-active sites are normally unstable. PASERS also leads to a unique way of studying complex interfacial kinetic processes by controlling the voltage pulse height, frequency, and shape. Moreover, the measurement of time-resolved spectra in the very low vibrational frequency region can be achieved by PASERS with the use of a conventional scanning spectrometer with a single-channel detector. In this paper, the main advantages of PASERS are illustrated by studying two typical SERS systems, i.e., thiocyanate ion and thiourea adsorbed at silver electrodes, respectively. It is shown that the potential-averaging method can be applied as a common method to many other existing spectroelectrochemical techniques.

scholarly journals Optimizing electroporation assisted silver nanoparticle delivery into living C666 cells for surface-enhanced Raman spectroscopy

2011 ◽  
Vol 25 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Yun Yu ◽  
Juqiang Lin ◽  
Yanan Wu ◽  
Shangyuan Feng ◽  
Yongzeng Li ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Spectrum ◽  
Electric Pulses ◽  
Nanoparticle Delivery ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Delivery Efficiency

Electroporation assisted metallic nanoparticle delivery has been shown by our previous work to significantly reduce the time of sample preparation for surface-enhanced Raman spectroscopy (SERS) measurements of biological cells. In this paper, we report our experimental work to optimize the electroporation parameters, including adjustment of the pulse pattern, operation temperature, and electroporation buffer, for fastest delivery of silver nanoparticles into living C666 cells (a human nasopharyngeal carcinoma cell line). The delivery efficiency was evaluated by the integrated intensity of whole cell SERS spectrum. Our work concluded that the silver nanoparticle delivery rate is best under the electroporation condition of using 4 consecutive 350 V (875 V/cm) rectangular electric pulses of 1, 10, 10 and 1 ms durations, respectively. Low temperature (0–4°C) is necessary for keeping cell viability during the electroporation process and it also improves the delivery efficiency of silver nanoparticles. The serum in the buffer has no obvious effect on the delivery efficiency.

Bacterial detection and differentiation via direct volatile organic compound sensing with surface enhanced Raman spectroscopy

2017 ◽  
Author(s):  
Caitlin S. DeJong ◽  
David I. Wang ◽  
Aleksandr Polyakov ◽  
Anita Rogacs ◽  
Steven J. Simske ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bacterial Infections ◽  
Direct Detection ◽  
Point Of Care ◽  
Surface Enhanced Raman Spectroscopy ◽  
E Coli ◽  
Recent Emergence ◽  
Surface Enhanced ◽  
Volatile Organic ◽  
Surface Enhanced Raman

Through the direct detection of bacterial volatile organic compounds (VOCs), via surface enhanced Raman spectroscopy (SERS), we report here a reconfigurable assay for the identification and monitoring of bacteria. We demonstrate differentiation between highly clinically relevant organisms: <i>Escherichia coli</i>, <i>Enterobacter cloacae</i>, and <i>Serratia marcescens</i>. This is the first differentiation of bacteria via SERS of bacterial VOC signatures. The assay also detected as few as 10 CFU/ml of <i>E. coli</i> in under 12 hrs, and detected <i>E. coli</i> from whole human blood and human urine in 16 hrs at clinically relevant concentrations of 10<sup>3</sup> CFU/ml and 10<sup>4</sup> CFU/ml, respectively. In addition, the recent emergence of portable Raman spectrometers uniquely allows SERS to bring VOC detection to point-of-care settings for diagnosing bacterial infections.

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