scholarly journals Ultra-rapid on-site detection of SARS-CoV-2 infection using simple ATR-FTIR spectroscopy and analysis algorithm: high sensitivity and specificity

2020 ◽  
Author(s):  
Valério G. Barauna ◽  
Maneesh N. Singh ◽  
Leonardo Leal Barbosa ◽  
Wena Dantas Marcarini ◽  
Paula Frizera Vassallo ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Ftir Spectroscopy ◽  
Rna Virus ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Test System ◽  
Attenuated Total Reflection ◽  
Spectral Signature ◽  
Linear Discriminant ◽  
Ftir Spectral Analysis

AbstractThere is an urgent need for ultra-rapid testing regimens to detect the SARS-CoV-2 [Severe Acute Respiratory Syndrome Coronavirus 2] virus infections in real-time within seconds to stop its spread. Current testing approaches for this RNA virus focus primarily on diagnosis by RT-qPCR, which is time-consuming, costly, often inaccurate and impractical for general population rollout due to the need for laboratory processing. The latency until the test result arrives with the patient has led to further virus spread. Furthermore, latest antigen rapid tests still require 15 to 30 min processing time and are challenging to handle. Despite increased PCR-test and antigen-test efforts the pandemic has entered the worldwide second stage. Herein, we applied a superfast reagent-free and non-destructive approach of attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy with subsequent chemometric analysis to the interrogation of virus-infected samples. Contrived samples with inactivated gamma-irradiated Covid-19 virus particles at levels down to 1582 copies/ml generated infrared (IR) spectra with good signal-to-noise ratio. Predominant virus spectral peaks are associated with nucleic acid bands, including RNA. At low copy numbers, the presence of virus particle was found to be capable of modifying the IR spectral signature of saliva, again with discriminating wavenumbers primarily associated with RNA. Discrimination was also achievable following ATR-FTIR spectral analysis of swabs immersed in saliva variously spiked with virus. Following on, we nested our test system in a clinical setting wherein participants were recruited to provide demographic details, symptoms, parallel RT-qPCR testing and the acquisition of pharyngeal swabs for ATR-FTIR spectral analysis. Initial categorisation of swab samples into negative versus positive Covid-19 infection was based on symptoms and PCR results. Following training and validation of a genetic algorithm-linear discriminant analysis (GA-LDA) algorithm, a blind sensitivity of 95% and specificity of 89% was achieved. This prompt approach generates results within two minutes and is applicable in areas with increased people traffic that require sudden test results such as airports, events or gate controls.

scholarly journals ATR-FTIR Spectral Analysis of Ferns Using as Fingerprint for Identification of Fern Species

2019 ◽  
Vol 70 (3) ◽  
pp. 875-880
Author(s):  
Carmen Mihaela Topala ◽  
Alina Paunescu ◽  
Liliana Cristina Soare
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Data Analysis ◽  
Ftir Spectroscopy ◽  
Multivariate Data Analysis ◽  
Functional Group ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Ftir Spectral Analysis ◽  
Fern Species

This study used Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy to provided detail information of the organic functional group of secondary metabolites, produced by ferns. The study showed ATR-FTIR spectra of nine fern species: Asplenium scolopendrium, Asplenium trichomanes, Asplenium trichomanes-ramosum, Athyrium filix-femina, Dryopteris affinis, Dryopteris filix-mas, Polypodium vulgare, Polystichum lobatum and Phegopteris connectilis. After comparison of each plant FTIR region divided in three areas: 2800-3000 cm-1 (aliphatic region), 1600-1800 cm-1 (distinct oxygenated groups) and 700-900 cm-1 (aromatic bands). ATR-FTIR Spectroscopy combined with multivariate data analysis have been applied for the discrimination of 9 fern species.

scholarly journals ATR-FTIR spectroscopy in blood plasma combined with multivariate analysis to detect HIV infection in pregnant women

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lidiane G. Silva ◽  
Ana F. S. Péres ◽  
Daniel L. D. Freitas ◽  
Camilo L. M. Morais ◽  
Francis L. Martin ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Blood Plasma ◽  
Pregnant Women ◽  
Ftir Spectroscopy ◽  
Vertical Transmission ◽  
Low Cost ◽  
Attenuated Total Reflection ◽  
Primary Concern ◽  
Linear Discriminant ◽  
Analytical Frequency

AbstractThe primary concern for HIV-infected pregnant women is the vertical transmission that can occur during pregnancy, in the intrauterine period, during labour or even breastfeeding. The risk of vertical transmission can be reduced by early diagnosis. Therefore, it is necessary to develop new methods to detect this virus in a quick and low-cost fashion, as colorimetric assays for HIV detection tend to be laborious and costly. Herein, attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy combined with multivariate analysis was employed to distinguish HIV-infected patients from healthy uninfected controls in a total of 120 blood plasma samples. The best sensitivity (83%) and specificity (92%) values were obtained using the genetic algorithm with linear discriminant analysis (GA-LDA). These good classification results in addition to the potential for high analytical frequency, the low cost and reagent-free nature of this method demonstrate its potential as an alternative tool for HIV screening during pregnancy.

scholarly journals Spectrochemical differentiation in gestational diabetes mellitus based on attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy and multivariate analysis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Emanuelly Bernardes-Oliveira ◽  
Daniel Lucas Dantas de Freitas ◽  
Camilo de Lelis Medeiros de Morais ◽  
Maria da Conceição de Mesquita Cornetta ◽  
Juliana Dantas de Araújo Santos Camargo ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Multivariate Analysis ◽  
Fourier Transform ◽  
Discriminant Analysis ◽  
Gestational Diabetes ◽  
Gestational Diabetes Mellitus ◽  
Ftir Spectroscopy ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Linear Discriminant

Abstract Gestational diabetes mellitus (GDM) is a hyperglycaemic imbalance first recognized during pregnancy, and affects up to 22% of pregnancies worldwide, bringing negative maternal–fetal consequences in the short- and long-term. In order to better characterize GDM in pregnant women, 100 blood plasma samples (50 GDM and 50 healthy pregnant control group) were submitted Attenuated Total Reflection Fourier-transform infrared (ATR-FTIR) spectroscopy, using chemometric approaches, including feature selection algorithms associated with discriminant analysis, such as Linear Discriminant Analysis (LDA), Quadratic Discriminant Analysis (QDA) and Support Vector Machines (SVM), analyzed in the biofingerprint region between 1800 and 900 cm−1 followed by Savitzky–Golay smoothing, baseline correction and normalization to Amide-I band (~ 1650 cm−1). An initial exploratory analysis of the data by Principal Component Analysis (PCA) showed a separation tendency between the two groups, which were then classified by supervised algorithms. Overall, the results obtained by Genetic Algorithm Linear Discriminant Analysis (GA-LDA) were the most satisfactory, with an accuracy, sensitivity and specificity of 100%. The spectral features responsible for group differentiation were attributed mainly to the lipid/protein regions (1462–1747 cm−1). These findings demonstrate, for the first time, the potential of ATR-FTIR spectroscopy combined with multivariate analysis as a screening tool for fast and low-cost GDM detection.

scholarly journals Spectrochemical differentiation of meningioma tumours based on attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy

2019 ◽  
Vol 412 (5) ◽  
pp. 1077-1086
Author(s):  
Taha Lilo ◽  
Camilo L. M. Morais ◽  
Katherine M. Ashton ◽  
Ana Pardilho ◽  
Charles Davis ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Discriminant Analysis ◽  
Ftir Spectroscopy ◽  
Principal Component ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Tissue Samples ◽  
Linear Discriminant ◽  
Grade Ii

AbstractMeningiomas are the commonest types of tumours in the central nervous system (CNS). It is a benign type of tumour divided into three WHO grades (I, II and III) associated with tumour growth rate and likelihood of recurrence, where surgical outcomes and patient treatments are dependent on the meningioma grade and histological subtype. The development of alternative approaches based on attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy could aid meningioma grade determination and its biospectrochemical profiling in an automated fashion. Herein, ATR-FTIR in combination with chemometric techniques is employed to distinguish grade I, grade II and grade I meningiomas that re-occurred. Ninety-nine patients were investigated in this study where their formalin-fixed paraffin-embedded (FFPE) brain tissue samples were analysed by ATR-FTIR spectroscopy. Subsequent classification was performed via principal component analysis plus linear discriminant analysis (PCA-LDA) and partial least squares plus discriminant analysis (PLS-DA). PLS-DA gave the best results where grade I and grade II meningiomas were discriminated with 79% accuracy, 80% sensitivity and 73% specificity, while grade I versus grade I recurrence and grade II versus grade I recurrence were discriminated with 94% accuracy (94% sensitivity and specificity) and 97% accuracy (97% sensitivity and 100% specificity), respectively. Several wavenumbers were identified as possible biomarkers towards tumour differentiation. The majority of these were associated with lipids, protein, DNA/RNA and carbohydrate alterations. These findings demonstrate the potential of ATR-FTIR spectroscopy towards meningioma grade discrimination as a fast, low-cost, non-destructive and sensitive tool for clinical settings.

Thermal Decomposition of Li(NTO)·2H2O and Na(NTO)·H2O (NTO = Anion of 3-Nitro-1,2,4-triazol-5-one): Kinetics Derived from T-jump/FTIR Spectroscopy

2006 ◽  
Vol 71 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Yuanhua Sun ◽  
Tonglai Zhang ◽  
Jianguo Zhang ◽  
Xiaojing Qiao ◽  
Li Yang ◽  
...  
Keyword(s):  
Ftir Spectroscopy ◽  
Energetic Material ◽  
Burning Surface ◽  
High Sensitivity ◽  
Control Voltage ◽  
Differential Scanning Colorimetry ◽  
Voltage Trace ◽  
Dsc Method ◽  
Phase Chemistry ◽  
Kinetics Of

A "snapshot" simulation of the surface reaction zone is captured by a thin film of material heated rapidly to temperatures characteristic of the burning surface by using the T-jump/FTIR spectroscopy. The time-to-exotherm (tx) kinetics method derived from the control voltage trace of the Pt filament can be introduced to resolve the kinetics of an energetic material owing to its high sensitivity to the thermochemical reactions. The kinetic parameters of the two title compounds are determined under different pressures. The results show that Li(NTO)·2H2O and Na(NTO)·H2O (NTO = anion of 3-nitro-1,2,4-triazol-5-one) exhibit weak pressure dependence, their decomposition is dominated by the condensed phase chemistry irrespective of the pressure in the 0.1-1.1 MPa range. The values of Ea determined here are smaller than those given by a traditional non-isothermal differential scanning colorimetry (DSC) method, which might be resembled as the surface of explosion more closely and enabled the pyrolysis surface to be incorporated into models of steady and possibly unsteady combustion. The kinetics can also be successfully used to understand the behavior of the energetic material in practical combustion problems.

scholarly journals Ultrarapid On-Site Detection of SARS-CoV-2 Infection Using Simple ATR-FTIR Spectroscopy and an Analysis Algorithm: High Sensitivity and Specificity

2021 ◽  
Vol 93 (5) ◽  
pp. 2950-2958
Author(s):  
Valério G. Barauna ◽  
Maneesh N. Singh ◽  
Leonardo Leal Barbosa ◽  
Wena Dantas Marcarini ◽  
Paula Frizera Vassallo ◽  
...  
Keyword(s):  
Ftir Spectroscopy ◽  
Sensitivity And Specificity ◽  
High Sensitivity ◽  
Analysis Algorithm

scholarly journals The Double Face of Ketamine—The Possibility of Its Identification in Blood and Beverages

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 813
Author(s):  
Magdalena Świądro ◽  
Paweł Stelmaszczyk ◽  
Irena Lenart ◽  
Renata Wietecha-Posłuszny
Keyword(s):  
Date Rape ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Heroin Addiction ◽  
Assisted Extraction ◽  
Low Concentrations ◽  
High Concentrations ◽  
Rosé Wine ◽  
Tof Ms

The purpose of this study was to develop and validate a high-sensitivity methodology for identifying one of the most used drugs—ketamine. Ketamine is used medicinally to treat depression, alcoholism, and heroin addiction. Moreover, ketamine is the main ingredient used in so-called “date-rape” pills (DRP). This study presents a novel methodology for the simultaneous determination of ketamine based on the Dried Blood Spot (DBS) method, in combination with capillary electrophoresis coupled with a mass spectrometer (CE-TOF-MS). Then, 6-mm circles were punched out from DBS collected on Whatman DMPK-C paper and extracted using microwave-assisted extraction (MAE). The assay was linear in the range of 25–300 ng/mL. Values of limits of detection (LOD = 6.0 ng/mL) and quantification (LOQ = 19.8 ng/mL) were determined based on the signal to noise ratio. Intra-day precision at each determined concentration level was in the range of 6.1–11.1%, and inter-day between 7.9–13.1%. The obtained precision was under 15.0% (for medium and high concentrations) and lower than 20.0% (for low concentrations), which are in accordance with acceptance criteria. Therefore, the DBS/MAE/CE-TOF-MS method was successfully checked for analysis of ketamine in matrices other than blood, i.e., rose wine and orange juice. Moreover, it is possible to identify ketamine in the presence of flunitrazepam, which is the other most popular ingredient used in DRP. Based on this information, the selectivity of the proposed methodology for identifying ketamine in the presence of other components of rape pills was checked.

scholarly journals Mid-infrared photoacoustic gas monitoring driven by a gas-filled hollow-core fiber laser

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yazhou Wang ◽  
Yuyang Feng ◽  
Abubakar I. Adamu ◽  
Manoj K. Dasa ◽  
J. E. Antonio-Lopez ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Laser Source ◽  
High Signal ◽  
Mid Infrared ◽  
Raman Fiber Laser ◽  
Custom Made ◽  
Core Fiber ◽  
Detection Technologies

AbstractDevelopment of novel mid-infrared (MIR) lasers could ultimately boost emerging detection technologies towards innovative spectroscopic and imaging solutions. Photoacoustic (PA) modality has been heralded for years as one of the most powerful detection tools enabling high signal-to-noise ratio analysis. Here, we demonstrate a novel, compact and sensitive MIR-PA system for carbon dioxide (CO2) monitoring at its strongest absorption band by combining a gas-filled fiber laser and PA technology. Specifically, the PA signals were excited by a custom-made hydrogen (H2) based MIR Raman fiber laser source with a pulse energy of ⁓ 18 μJ, quantum efficiency of ⁓ 80% and peak power of ⁓ 3.9 kW. A CO2 detection limit of 605 ppbv was attained from the Allan deviation. This work constitutes an alternative method for advanced high-sensitivity gas detection.

scholarly journals Assessing the usefulness of acute physiological responses following resistance exercise: sensitivity, magnitude of change, and time course of measures

2019 ◽  
Vol 44 (3) ◽  
pp. 309-319 ◽  
Author(s):  
Joshua S. Jackman ◽  
Phillip G. Bell ◽  
Simone Gill ◽  
Ken van Someren ◽  
Gareth W. Davison ◽  
...  
Keyword(s):  
Resistance Exercise ◽  
Time Course ◽  
Signal To Noise Ratio ◽  
Physiological Responses ◽  
High Sensitivity ◽  
Maximal Voluntary Isometric Contraction ◽  
Reactive Protein ◽  
Adaptation Processes ◽  
Exercise Stimulus ◽  
Metalloproteinase 9

A variety of strategies exist to modulate the acute physiological responses following resistance exercise aimed at enhancing recovery and/or adaptation processes. To assess the true impact of these strategies, it is important to know the ability of different measures to detect meaningful change. We investigated the sensitivity of measures used to quantify acute physiological responses to resistance exercise and constructed a physiological profile to characterise the magnitude of change and the time course of these responses. Eight males accustomed to regular resistance exercise performed experimental sessions during a “control week”, void of an exercise stimulus. The following week, termed the “exercise week”, participants repeated this sequence of experimental sessions, and they also performed a bout of lower-limb resistance exercise following the baseline assessments. Assessments were conducted at baseline and at 2, 6, 24, 48, 72, and 96 h after the intervention. On the basis of the signal-to-noise ratio, the most sensitive measures were maximal voluntary isometric contraction, 20-m sprint, countermovement jump peak force, rate of force development (100–200 ms), muscle soreness, Daily Analysis Of Life Demands For Athletes part B, limb girth, matrix metalloproteinase-9, interleukin-6, creatine kinase, and high-sensitivity C-reactive protein with ratios >1.5. Clear changes in these measures following resistance exercise were determined via magnitude-based inferences. These findings highlight measures that can detect real changes in acute physiological responses following resistance exercise in trained individuals. Researchers investigating strategies to manipulate acute physiological responses for recovery and/or adaptation can use these measures, as well as the recommended sampling points, to be confident that their interventions are making a worthwhile impact.

Model Optimization and Stability of Hemoglobin Analysis in Human Soluble Blood Samples by FTIR/ATR Spectroscopy

2011 ◽  
Vol 55-57 ◽  
pp. 1168-1171
Author(s):  
Tao Pan ◽  
Ai Hong Peng ◽  
Wen Jie Huang
Keyword(s):  
Signal To Noise Ratio ◽  
Attenuated Total Reflection ◽  
Partial Least Square ◽  
Least Square ◽  
Model Optimization ◽  
Optimal Model ◽  
Blood Samples ◽  
Quantification Method ◽  
Atr Spectroscopy ◽  
Pls Method

Using Fourier transform infrared spectroscopy (FTIR), attenuated total reflection (ATR) technology and partial least square (PLS) method, the rapid quantification method of hemoglobin (HGB) in human soluble blood samples was established. Based on the distribution of samples’ HGB chemical value and absorbance on 1543 cm-1 which had the highest signal to noise ratio for HGB, all samples were divided into calibration set and prediction set for 50 times. PLS models were established for all divisions, based on the average data RMSEPAve, the stable optimal model was selected, the corresponding PLS factor, RMSEPAve and RP,Ave were 2, 6.81 g/L and 0.943 respectively.

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