Rapid recognition of volatile organic compounds with colorimetric sensor arrays for lung cancer screening

Abstract

Volatile organic compounds (VOCs) in breath can be used as biomarkers to identify early stages of lung cancer. Herein, we report a disposable colorimetric array that has been constructed from diverse chemo-responsive colorants. Distinguishable difference maps were plotted within 4 min for specifically targeted VOCs. Through the consideration of various chemical interactions with VOCs, the arrays successfully discriminate between 20 different volatile organic compounds in breath that are related to lung cancer. VOCs were identified either with the visualized difference maps or through pattern recognition with an accuracy of at least 90%. No uncertainties or errors were observed in the hierarchical cluster analysis (HCA). Finally, good reproducibility and stability of the array was achieved against changes in humidity. Generally, this work provides fundamental support for construction of simple and rapid VOC sensors. More importantly, this approach provides a hypothesis-free array method for breath testing via VOC profiling. Therefore, this small, rapid, non-invasive, inexpensive, and visualized sensor array is a powerful and promising tool for early screening of lung cancer. Graphical abstract A disposable colorimetric array has been developed with broadly chemo-responsive dyes to incorporate various chemical interactions, through which the arrays successfully discriminate 20 VOCs that are related to lung cancer via difference maps alone or chemometrics within 4 min. The hydrophobic porous matrix provides good stability against changes in humidity.

Emerging non‑invasive detection methodologies for lung cancer (Review)

“…Handa et al (72) investigated the breath samples of 50 patients with LC and 39 healthy controls by IMS and revealed that this method had a sensitivity of 81.3% and specificity of 89.7%. Nonetheless, sensors and IMS are limited in terms of detection and, thus, are usually coupled with complex algorithms (72)(73)(74). The advantages and disadvantages of nucleic acid-based (75-78), protein-based (79) and cell-based (80,81) detections were compared with VOC-based detection as displayed in Table I.…”

Breath Analysis: A Promising Tool for Disease Diagnosis—The Role of Sensors

“…Concerning cross-reactive sensing systems, there are five possible categories to which an indicator may belong to: pH responsive, (Brønsted acidity/basicity); metal-ion-containing dyes (Lewis basicity—electron pair donation); redox-responsive metal salts; nucleophilic indicators (responsive to electrophilic analytes) and dyes with large permanent dipoles (e.g., solvatochromic dyes) [ 6 ]. Such optical sensors have been extensively investigated in the field of breath analysis, mainly for LC diagnosis, using both synthetic [ 140 , 193 ] and real-world breath samples [ 127 , 194 ]. Hou et al have achieved to discriminate at first 4 ( Table 2 ) [ 140 ] and then 20 [ 193 ] LC-related VOCs in two separate studies, with accuracies of 100% and 90%, respectively.…”

“…Such optical sensors have been extensively investigated in the field of breath analysis, mainly for LC diagnosis, using both synthetic [ 140 , 193 ] and real-world breath samples [ 127 , 194 ]. Hou et al have achieved to discriminate at first 4 ( Table 2 ) [ 140 ] and then 20 [ 193 ] LC-related VOCs in two separate studies, with accuracies of 100% and 90%, respectively. Mazzone et al achieved to differentiate LC patients and HC, with moderate accuracies [ 127 , 194 ], as well as LC patients of different histologies with a higher accuracy percentage ( Table 2 ) [ 127 ].…”

Advancements in Microfabricated Gas Sensors and Microanalytical Tools for the Sensitive and Selective Detection of Odors

“…Colorimetric gas sensors can provide highly selective and discriminatory responses towards mixtures of various VOCs; hence, they are normally employed in e-noses for the detection of multiple odors and compounds [ 44 ]. Similar to interferometric devices, sensitivities of colorimetric gas sensors are generally at a few ppm and detection limits can be down to hundreds of ppb.…”