# The Use of Biological Sensors and Instrumental Analysis to Discriminate COVID-19 Odor Signatures
## 5 Conclusions  
Together, the completed experiments demonstrate the capacity to simultaneously create and test instrumental and biological approaches for the detection of novel odor signatures. This ability was expressed through the discrimination of COVID-19 expression in body odor collected on T-shirts. Both experiments demonstrate the capacity of human body odor to be used as a sample source for determining COVID-19 status. The described methods were characterized by different assets: (a) a rapid, mobile approach implementing canines and (b) a reagent-free instrumental analysis method with high degrees of reproducibility. The two highest performing canines were able to distinguish the COVID-19 positive and negative individuals with an average performance of 88% sensitivity and 95% specificity; building upon this, the instrumental model (with pet interferets removed) reached an ideal performance of 100% sensitivity and 100% specificity. Ideally, in future work, both methods can be used in conjunction to be able to efficiently screen and detect diseases in a noninvasive manner. In this work, the issues that hindered one experiment were not seen to affect both. Moving forward, it is suggested that multiple relevant COVID-19 variants be included in the training samples for both approaches, as it was seen to affect diagnostic performance in a previous canine study. Further concurrent investigations of combined canine and instrumental detection schemes may shed light on how to overcome issues in one approach, informed by the other. **Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/bios12111003/s1](https://www.mdpi.com/article/10.3390/bios12111003/s1)]([https://www.mdpi.com/article/10.3390/bios12111003/s1](https://www.mdpi.com/article/10.3390/bios12111003/s1)), Table S1: Canine Training Samples-Health Survey Results; Table S2: Canine Test Samples-Health Survey Results. **Author Contributions:** Conceptualization, C.M.O. and H.K.H. ; methodology, J.C.-C., A.M. and S.A.K. ; software, V.A.G. ; validation, J.C.-C. and V.A.G. ; formal analysis, V.A.G., J.C.-C. and A.M.; data curation, V.A.G., J.C.-C., A.M., A.C., S.A.K., E.N. and C.M.O. ; investigation, J.C.-C.; resources, B.S.A., K.G.F. and C.M.O. ; writing--original draft preparation, A.C. and V.P. ; writing--review and editing, V.A.G., J.C.-C., A.M., S.A.K., A.C. and C.M.O. ; visualization, V.A.G. ; supervision, H.K.H. ; project administration, K.G.F., A.T.C.J. and C.M.O. ; funding acquisition, K.G.F. and A.T.C.J. All authors have read and agreed to the published version of the manuscript. **Funding:** This research was funded by the NIH National Center for Advancing Translational Sciences 1-U18-Tr-003775-01. **Institutional Review Board Statement:** The study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Review Board of University of Pennsylvania (IRB/843534 approved on 06/26/2020). Additionally, the animal study protocol was approved by the Institutional Animal Care and Use Committee of University of Pennsylvania (IACUC@806922 approved on 5/7/2020, IACUC@804900 approved on 11/5/2020). **Informed Consent Statement:** Informed consent was obtained via electronic signature (Qualtrics) or a scanned copy of the consent form with a written signature. Informed consent was acquired from all subjects involved in the study. **Acknowledgments:** Thank you to the Penn Acute Research Collaboration coordinator team at University of Pennsylvania for their processing of COVID-19 T-shirt samples. **Conflicts of Interest:** The authors declare no conflict of interest. This table shows the samples used in the canine tests and the elapsed time between collection and the earliest and latest test done with the dogs.