scholarly journals Advances in Mid-Infrared Spectroscopy-Based Sensing Techniques for Exhaled Breath Diagnostics

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2227 ◽  
Author(s):  
Ramya Selvaraj ◽  
Nilesh J. Vasa ◽  
S. M. Shiva Nagendra ◽  
Boris Mizaikoff

Human exhaled breath consists of more than 3000 volatile organic compounds, many of which are relevant biomarkers for various diseases. Although gas chromatography has been the gold standard for volatile organic compound (VOC) detection in exhaled breath, recent developments in mid-infrared (MIR) laser spectroscopy have led to the promise of compact point-of-care (POC) optical instruments enabling even single breath diagnostics. In this review, we discuss the evolution of MIR sensing technologies with a special focus on photoacoustic spectroscopy, and its application in exhaled breath biomarker detection. While mid-infrared point-of-care instrumentation promises high sensitivity and inherent molecular selectivity, the lack of standardization of the various techniques has to be overcome for translating these techniques into more widespread real-time clinical use.

2021 ◽  
Author(s):  
Ahmed Mehaney ◽  
Hussein A. Elsayed ◽  
Ashour M. Ahmed

Abstract Detection of blood-carried volatile organic compounds (VOCs) existing in the exhaled breath of human is an attractive research point for noninvasive diagnosis of diseases. In this research, we introduce a novel application of photonic crystals (PCs) for the detection of isoprene traces in the exhaled breath as a biomarker for liver fibrosis. This idea is introduced for the first time according to the best of our knowledge. The proposed sensor structure is a one-dimensional (1D) PC constructed from a multilayer stack of two dielectric materials covered with an air cavity layer filled with the dry exhaled breath (DEB) and a thin metallic layer of Au is attached on the top surface. Hence, the proposed sensor is configured as, [prism/Au/air cavity/(GaN/SiO2)10]. The transfer matrix method and the Drude model are adopted to calculate the numerical simulations and reflection spectra of the design. The essential key for sensing isoprene levels is the resonant optical Tamm plasmon (TP) states within the photonic bandgap. The obtained numerical results are promising such as high sensitivity (S) of 0.321 nm/ppm or 278720 nm/RIU. This technique can be reducing the risk of infection during the taking of blood samples by syringe. Also, it can prevent the pain of patients. Finally, this work opens the door for the detection of many diseases by analyzing the breaths of patients based on photonic crystals.


Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 516 ◽  
Author(s):  
Veasna Soum ◽  
Sooyong Park ◽  
Albertus Ivan Brilian ◽  
Oh-Sun Kwon ◽  
Kwanwoo Shin

Recent advanced paper-based microfluidic devices provide an alternative technology for the detection of biomarkers by using affordable and portable devices for point-of-care testing (POCT). Programmable paper-based microfluidic devices enable a wide range of biomarker detection with high sensitivity and automation for single- and multi-step assays because they provide better control for manipulating fluid samples. In this review, we examine the advances in programmable microfluidics, i.e., paper-based continuous-flow microfluidic (p-CMF) devices and paper-based digital microfluidic (p-DMF) devices, for biomarker detection. First, we discuss the methods used to fabricate these two types of paper-based microfluidic devices and the strategies for programming fluid delivery and for droplet manipulation. Next, we discuss the use of these programmable paper-based devices for the single- and multi-step detection of biomarkers. Finally, we present the current limitations of paper-based microfluidics for biomarker detection and the outlook for their development.


2017 ◽  
Vol 50 (6) ◽  
pp. 1700919 ◽  
Author(s):  
Kevin Lamote ◽  
Matthijs Vynck ◽  
Olivier Thas ◽  
Joris Van Cleemput ◽  
Kristiaan Nackaerts ◽  
...  

Malignant pleural mesothelioma (MPM) is predominantly caused by asbestos exposure and has a poor prognosis. Breath contains volatile organic compounds (VOCs) and can be explored as an early detection tool. Previously, we used multicapillary column/ion mobility spectrometry (MCC/IMS) to discriminate between patients with MPM and asymptomatic high-risk persons with a high rate of accuracy. Here, we aim to validate these findings in different control groups.Breath and background samples were obtained from 52 patients with MPM, 52 healthy controls without asbestos exposure (HC), 59 asymptomatic former asbestos workers (AEx), 41 patients with benign asbestos-related diseases (ARD), 70 patients with benign non-asbestos-related lung diseases (BLD) and 56 patients with lung cancer (LC).After background correction, logistic lasso regression and receiver operating characteristic (ROC) analysis, the MPM group was discriminated from the HC, AEx, ARD, BLD and LC groups with 65%, 88%, 82%, 80% and 72% accuracy, respectively. Combining AEx and ARD patients resulted in 94% sensitivity and 96% negative predictive value (NPV). The most important VOCs selected were P1, P3, P7, P9, P21 and P26.We discriminated MPM patients from at-risk subjects with great accuracy. The high sensitivity and NPV allow breath analysis to be used as a screening tool for ruling out MPM.


2019 ◽  
Vol 55 (2) ◽  
pp. 1900544 ◽  
Author(s):  
Paul Brinkman ◽  
Waqar M. Ahmed ◽  
Cristina Gómez ◽  
Hugo H. Knobel ◽  
Hans Weda ◽  
...  

IntroductionAsthma is a heterogeneous condition, characterised by chronic inflammation of the airways, typically managed with inhaled bronchodilators and corticosteroids. In the case of uncontrolled asthma, oral corticosteroids (OCSs) are often prescribed. Good adherence and inhalation technique are associated with improved outcomes; however, it is difficult to monitor appropriate drug intake and effectiveness in individual patients. Exhaled breath contains thousands of volatile organic compounds (VOCs) that reflect changes in the body's chemistry and may be useful for monitoring drug pharmacokinetics/pharmacodynamics. We aimed to investigate the association of exhaled VOCs in severe asthma patients from the U-BIOPRED cohort (by gas chromatography coupled with time-of-flight mass spectrometry) with urinary levels of salbutamol and OCSs (by liquid chromatography coupled with high-resolution mass spectrometry).MethodsSamples were collected at baseline and after 12–18 months of follow-up. Statistical analysis was based on univariate and multivariate modelling, followed by area under the receiver operating characteristic curve (AUC) calculation. Results were verified through longitudinal replication and independent validation.ResultsData were available for 78 patients (baseline n=48, replication n=30 and validation n=30). Baseline AUC values were 82.1% (95% CI 70.4–93.9%) for salbutamol and 78.8% (95% CI 65.8–91.8%) for OCS. These outcomes could be adequately replicated and validated. Additional regression analysis between qualified exhaled VOCs and urinary concentrations of salbutamol and prednisone showed statistically significant correlations (p<0.01).ConclusionWe have linked exhaled VOCs to urinary detection of salbutamol and OCSs. This merits further development of breathomics into a point-of-care tool for therapeutic drug monitoring.


2020 ◽  
Vol 21 (24) ◽  
pp. 9416
Author(s):  
Johann-Christoph Licht ◽  
Hartmut Grasemann

Respiratory tract infections are common, and when affecting the lower airways and lungs, can result in significant morbidity and mortality. There is an unfilled need for simple, non-invasive tools that can be used to screen for such infections at the clinical point of care. The electronic nose (eNose) is a novel technology that detects volatile organic compounds (VOCs). Early studies have shown that certain diseases and infections can result in characteristic changes in VOC profiles in the exhaled breath. This review summarizes current knowledge on breath analysis by the electronic nose and its potential for the detection of respiratory diseases with and without infection.


Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout

This review details the fundamentals, working principles and recent developments of Schottky junctions based on 2D materials to emphasize their improved gas sensing properties including low working temperature, high sensitivity, and selectivity.


2017 ◽  
Author(s):  
Caitlin S. DeJong ◽  
David I. Wang ◽  
Aleksandr Polyakov ◽  
Anita Rogacs ◽  
Steven J. Simske ◽  
...  

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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