key: cord-0886838-3d0tmydv authors: de Carvalho, Luis Felipe das Chagas e Silva; Nogueira, Marcelo Saito title: Optical techniques for fast screening – towards prevention of the coronavirus COVID-19 outbreak date: 2020-04-15 journal: Photodiagnosis Photodyn Ther DOI: 10.1016/j.pdpdt.2020.101765 sha: 7e6592c68cd4a0473625371bbf1fb65f101ef75e doc_id: 886838 cord_uid: 3d0tmydv • Coronavirus disease 2019 (COVID-19) is emerging and requires early diagnostics. • Biomarkers are present for coronaviruses. • Raman and FT-IR spectroscopy are green technologies capable of high-throughput virus sensing. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The increasing need of high-throughput virus sensing is emerging due to the Coronavirus disease 2019 (COVID -19) outbreak. This letter focuses on increasing the awareness academic institutions about the possibility of incorporating vibrational spectroscopy techniques (Raman and Fourier-transform infrared (FT-IR) spectroscopy) for healthcare, especially motivating researchers to address COVID-19 related topics. We believe that those techniques are sensitive to the virus and can assist in the early and fast diagnosis to contain the new pandemic. COVID-19 is the latest biological hazard to pose threat to healthcare, political, economic and social sectors worldwide. Countries whi ch are part of the developed or under development world could have benefitted from technologies able to perform high throughput COVID -19 sensing to prevent the virus outbreak [1, 2] . The infection is associated to strains of SARS-CoV-2 virus. Since the SARS-CoV-2 can be transmitted by direct routes including cough, sneeze, and droplet inhalation and contact routes such as contact with nasal, oral, and eye mucous membranes, the virus has been proven to be pr esent on human biofluids [3] . Biofluids include saliva, blood, and possibly sputum, tears, and wound secretion, which contain specific disease biomarkers such as pro teins, nucleic acids, lipids, carbohydrates, hormones, phosphate, carotenoids. Biomarkers are present in coronaviruses, as their constitution comprises a single strand of positive-sense RNA involved by structural proteins/glycoprotein and lipids of their nucleocapsid, matrix and envelope. In addition, the S protei n from coronavirus can bind to the host cellmembrane receptors to facilitate viral entry into cells including the human angiotensin converting enzyme 2 (ACE2) receptor [2] . These biomarkers can be targeted by molecular specific diagnostic tests such as vibrational spectroscopy. Raman and FT-IR are emerging methods that allow real-time, non-invasive and non-destructive analysis of biofluids and biological tissues [4, 5] . In terms of FT-IR spectroscopy, attenuated total reflectance (ATR) crystals allow biofluids analyzes performed in seconds. Raman spectroscopy is highly specific and can be used to analyze biofluids samples directly or to analyze the virus binding on ACE2 receptors of the host cells. In this case, exfoliative cytology or c ell cultures may allow another potential diagnostic option for cell analysis. State-of-the-art of vibrational spectroscopy are sufficiently flexible to incorporate label -free analysis of small sample sizes, which makes vibrational spectroscopy a green technology capable of high -throughput virus sensing. We believe the most effective way of using FT-IR and Raman spectroscopy to perform virus sensing is separating mass-screening and biomolecular characterization applications. Due to the portability and low-noise measurements provided by FT-IR ATR spectroscopy, it can be widely used for cost-effective mass screening at hospitals, clinics, airports, among other places. The strong molecular specificity and water-free signals of Raman spectroscopy allows the technique to be used for biochemical profiling of cells in biofluids and cell cultures. The analysis of cell biochemistry can be relatively fast in order to provide the intracellular changes correlated to the disease, especially molecular-specific associations between the host cell and the virus. These changes can be further related to the pathophysiology of the patients in the clinic and investigation of new treatment/containment modalities. The implementation of spectroscopic techniques is facilitated by the small sample size required, the real-time evaluation and the possibility of designing userfriendly software. By applying multivariate analysis to the mass screening data, systems showing colors for healthy, dubious and diseased cases could further fasten the screening and increase adherence rates. Once vibrational spectroscopy is applied in a large scale, the costs can be reduced and extended to low -resource settings, as the minimal sample preparation can keep operational costs low. Additional benefits of large-scale application of vibrational spectroscopy are the creation of an environment that supports the diagnosis of associated diseases. In general, we would like to reinforce the potential of COVID-19 studies using the techniques described in this letter. We are going through a dark moment when the diagnosis and treatment strategies for the disease are still premature. With this in mind, n ew modalities must be evaluated for the direct benefit of patients in order to accelerate the diagnostic process and contribute to the cure of COVID -19. Luis Felipe CS Carvalho is funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes) -PNPD Odontologia/UNITAU, and Centro Universitário Braz Cubas -Research Program Coronavirus disease 2019 ( COVID-19): situation report Laboratory Diagnosis of Emerging Human Coronavirus Infections -The State of the Art Transmission routes of 2019-nCoV and controls in dental practice Vibration spectroscopy and body biofluids: Literature review for clinical applications New insights of Raman spectroscopy for oral clinical applications Francisco Rodrigues Filho, 1233 -Vila Mogilar The authors declare no conflicts of interest.