Gold/bohemite substrates for SERS detection of hepcidin in saliva for fast hyperinflammation screening of covid-19 hyperinflammation

Gold/bohemite substrates for SERS detection of hepcidin in saliva for fast hyperinflammation screening of covid-19 hyperinflammation

• Autor
• Carla Carolina Silva Bandeira
• Co-autores
• Julian Mateo Rayo Alape , Herculano da Silva Martinho
• Resumo

• In 2019, the pandemic caused by the novel coronavirus severe acute respiratory syndrome (SARS-CoV-2) resulted in the emergence of the Covid-19 disease, triggering a global health crisis. Studies have substantiated that individuals with severe Covid-19 manifest cytokine storm syndrome [1], with the inflammatory cytokine interleukin-6 (IL-6) particularly prominent as an inducer of hepcidin. While the contribution of other cytokines is plausible, elevated levels of IL-6 have been observed to correlate with the severity of Covid-19 [2]. The remarkable potential of hepcidin as a biomarker has been evidenced, as it can be detected in various biological fluids such as blood, urine, and saliva [3].

  Various biological methods have been employed for Covid-19 diagnosis, including enzyme-linked immunosorbent assay (ELISA) and Real-Time Polymerase Chain Reaction (RT-PCR), the latter being deemed a standard method due to its numerous advantages [4]. Nevertheless, the imperative for faster and more reliable methods to meet the large-scale demand has arisen. In response to these needs, spectroscopic techniques, particularly Surface-Enhanced Raman Spectroscopy (SERS), have been explored. SERS inherits rich chemical information from Raman spectroscopy fingerprints and achieves enhanced excitation and scattering sensitivity through plasmonics. This amalgamation of Raman's intrinsic advantages with high sensitivity potentially enables even single-molecule detection [5].

  Indeed, SERS spectroscopy in serum and other biofluids for pathology diagnosis represents an emerging field, exhibiting promising preliminary results in various malignancies, as indicated by studies conducted by Moisoiu et al. [6] and Yamazoe et al. [7]. These studies are related to a substrate based on gold deposition at a diagonal angle to the nanostructure obtained by the oxidation of aluminum nano-layers (boehmite). The deposition results in the creation of nanostructured arrays resembling combs that generate "hot spots" conducive to SERS, facilitating the identification of cancer cells through body fluids, such as stool [8].

  Acknowledging the imperative for new methods to overcome the limitations of RT-PCR and recognizing the considerable potential of the SERS effect in diagnostics and biofluid screening, such as saliva for hepcidin detection, this study aimed to develop and test nanostructured substrates for SERS-based detection of the hepcidin metabolite in saliva, specifically for rapid Covid-19 screening applications.

   

  For the substrate development, aluminum film deposition was conducted, subsequently converted into boehmite film using the hydrothermal method, and ultimately complemented with a gold film. Morphological analysis of the substrate was performed using High-Resolution Field Emission Scanning Electron Microscopy (HR-FESEM) and Raman Spectroscopy. Subsequent tests on the substrate were conducted to analyze the hepcidin biomarker, revealing promising results for the SERS effect with Raman spectroscopy. Different wavelength lasers were employed to evaluate the optimal amplification factor.

• Palavras-chave
• Boehmite, Substrates, SERS, Hepcidin, Saliva, Hyperinflammation
• Modalidade
• Pôster
• Área Temática
• Nanociência e Nanotecnologia