Rapid and sensitive surface-enhanced Raman spectroscopy (SERS) method combined with gold nanoparticles for determination of paraquat in apple juice

2018 ◽  
Vol 98 (10) ◽  
pp. 3892-3898 ◽  
Author(s):  
Hairui Luo ◽  
Xiaohui Wang ◽  
Yiqun Huang ◽  
Keqiang Lai ◽  
Barbara A Rasco ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Raman Spectroscopy ◽  
Apple Juice ◽  
Surface Enhanced Raman Spectroscopy ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

scholarly journals Determination of the Immunoglobulin G Spectrum by Surface-Enhanced Raman Spectroscopy Using Quasispherical Gold Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Alejandra Ortiz-Dosal ◽  
Elizabeth Loredo-García ◽  
Ana Gabriela Álvarez-Contreras ◽  
Juan Manuel Núñez-Leyva ◽  
Luis Carlos Ortiz-Dosal ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Raman Spectroscopy ◽  
Raman Spectrum ◽  
Surface Enhanced Raman Spectroscopy ◽  
Protein Quantification ◽  
Acquisition Time ◽  
Sers Substrate ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Background. Immunoglobulins (Ig) are glycoprotein molecules produced by plasma cells in response to antigenic stimuli involved in various physiological and pathological conditions. Intravenous immunoglobulin (IVIG) is a compound whose composition corresponds to Ig concentrations in human plasma, predominantly IgG. It is used as a replacement treatment in immunodeficiencies and as an immunomodulator in inflammatory and autoimmune diseases. The determination of IgG concentrations is useful in the diagnosis of these immunodeficiencies. Surface-enhanced Raman spectroscopy (SERS) is a technique that allows protein quantification in a fast and straightforward way. Objective. This study is aimed at determining the Raman spectrum of IgG at physiological concentrations using quasispherical gold nanoparticles as a SERS substrate. Methods. We initially determined the Raman spectrum of IVIG at 5%. Subsequently, for SERS’ characterization, decreasing dilutions of the protein were made by adding deionized water and an equal volume of the 5 nm gold quasispherical nanoparticle colloid. For each protein concentration, the Raman spectrum was determined using a 10x objective; we focused the 532 and 785 nm laser on the sample surface, in a range of 500-1800 cm-1, with five acquisitions and an acquisition time of 30 seconds. Results. We obtained the IVIG spectrum using SERS up to a concentration of 75 mg/dl. The Raman bands correspond to aromatic amino acid side chains and the characteristic beta-sheet structure of IgG. Conclusion. The use of 5 nm quasispherical gold nanoparticles as a SERS substrate allows for detecting the Raman spectrum of IVIG at physiological concentrations.

Multivariate Analysis Aided Surface-Enhanced Raman Spectroscopy (MVA-SERS) Multiplex Quantitative Detection of Trace Fentanyl in Illicit Drug Mixtures Using a Handheld Raman Spectrometer

2021 ◽  
pp. 000370282110329
Author(s):  
Ling Wang ◽  
Mario O. Vendrell-Dones ◽  
Chiara Deriu ◽  
Sevde Doğruer ◽  
Peter de B. Harrington ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Principal Component ◽  
Surface Enhanced Raman Spectroscopy ◽  
Quantitative Detection ◽  
Least Squares Regression ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Sers Detection ◽  
Current Screening

Recently there has been upsurge in reports that illicit seizures of cocaine and heroin have been adulterated with fentanyl. Surface-enhanced Raman spectroscopy (SERS) provides a useful alternative to current screening procedures that permits detection of trace levels of fentanyl in mixtures. Samples are solubilized and allowed to interact with aggregated colloidal nanostars to produce a rapid and sensitive assay. In this study, we present the quantitative determination of fentanyl in heroin and cocaine using SERS, using a point-and-shoot handheld Raman system. Our protocol is optimized to detect pure fentanyl down to 0.20 ± 0.06 ng/mL and can also distinguish pure cocaine and heroin at ng/mL levels. Multiplex analysis of mixtures is enabled by combining SERS detection with principal component analysis and super partial least squares regression discriminate analysis (SPLS-DA), which allow for the determination of fentanyl as low as 0.05% in simulated seized heroin and 0.10% in simulated seized cocaine samples.

Sign in / Sign up

Export Citation Format

Share Document