Investigating temperature-dependent spectral changes in human saliva using SERS on Ag and Au surfaces

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F25%3A43933231" target="_blank" >RIV/60461373:22340/25:43933231 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0924203125000220" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0924203125000220</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.vibspec.2025.103788" target="_blank" >10.1016/j.vibspec.2025.103788</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Investigating temperature-dependent spectral changes in human saliva using SERS on Ag and Au surfaces

Popis výsledku v původním jazyce

Surface-enhanced Raman Scattering (SERS) Spectroscopy, combined with multivariate data analysis such as Principal Component Analysis (PCA), effectively detects subtle changes in complex biological samples. In this study, we applied SERS to identify subtle molecular changes in human saliva deposited on large nanostructured Ag and Au substrates, focusing on the influence of temperature variations ranging from 10 degrees C to 45 degrees C. The selected temperature intervals - 10 degrees C (cooling technology), 23 degrees C (laboratory temperature), 37 degrees C (physiological temperature), 42 degrees C (fever), and 45 degrees C (extreme temperatures) - reflect real-world conditions that biological and medical samples may encounter during collection, storage, transport, and analysis. We aimed to determine whether saliva samples remain stable at these temperatures over four days or if significant changes occur. Furthermore, we investigated the reversibility of spectral alterations during thermal jumps, where samples were heated to 45 degrees C and then cooled back to 10 degrees C. To ensure reliability, we utilized a computer-controlled mapping stage and a thermostatic sample holder, allowing precise temperature control and repeated recordings at identical locations on the substrate. Attention was given to intensity changes of marker bands, including band ratios, such as the ratio of 1175 cm-1 to 1005 cm-1 bands (protein hydration marker), the ratio of 856 cm-1 to 831 cm-1 bands (hydrophobicity marker of the environment surrounding tyrosine), and the ratio of 1360 cm-1 to 1340 cm-1 bands (hydrophobicity marker of the environment surrounding tryptophan) at different temperatures. The protein hydration marker exhibited a progressive decrease with increasing temperature, indicating water loss from the protein environment. In contrast, the hydrophobicity markers for tyrosine and tryptophan residues showed an increasing trend, suggesting enhanced hydrophobicity and a temperature-dependent reorganization of the protein structure on the SERS-active surfaces. In addition to these markers, we monitored changes related to amino acid residue bands for each temperature during the stability tests and thermal cycling. The spectral changes were associated with water loss and the reorganization of molecules near the nanostructured plasmonic surface, indicating saliva&apos;s sensitivity to temperature conditions. Our findings emphasize the importance of maintaining proper storage conditions for saliva films on large-area substrates to preserve sample integrity and prevent the misinterpretation of temperature-induced spectral changes. This study contributes to best practices for SERS analysis of thermally sensitive materials, particularly biofluids, especially in the context of medical diagnostics.

Název v anglickém jazyce

Investigating temperature-dependent spectral changes in human saliva using SERS on Ag and Au surfaces

Popis výsledku anglicky

Surface-enhanced Raman Scattering (SERS) Spectroscopy, combined with multivariate data analysis such as Principal Component Analysis (PCA), effectively detects subtle changes in complex biological samples. In this study, we applied SERS to identify subtle molecular changes in human saliva deposited on large nanostructured Ag and Au substrates, focusing on the influence of temperature variations ranging from 10 degrees C to 45 degrees C. The selected temperature intervals - 10 degrees C (cooling technology), 23 degrees C (laboratory temperature), 37 degrees C (physiological temperature), 42 degrees C (fever), and 45 degrees C (extreme temperatures) - reflect real-world conditions that biological and medical samples may encounter during collection, storage, transport, and analysis. We aimed to determine whether saliva samples remain stable at these temperatures over four days or if significant changes occur. Furthermore, we investigated the reversibility of spectral alterations during thermal jumps, where samples were heated to 45 degrees C and then cooled back to 10 degrees C. To ensure reliability, we utilized a computer-controlled mapping stage and a thermostatic sample holder, allowing precise temperature control and repeated recordings at identical locations on the substrate. Attention was given to intensity changes of marker bands, including band ratios, such as the ratio of 1175 cm-1 to 1005 cm-1 bands (protein hydration marker), the ratio of 856 cm-1 to 831 cm-1 bands (hydrophobicity marker of the environment surrounding tyrosine), and the ratio of 1360 cm-1 to 1340 cm-1 bands (hydrophobicity marker of the environment surrounding tryptophan) at different temperatures. The protein hydration marker exhibited a progressive decrease with increasing temperature, indicating water loss from the protein environment. In contrast, the hydrophobicity markers for tyrosine and tryptophan residues showed an increasing trend, suggesting enhanced hydrophobicity and a temperature-dependent reorganization of the protein structure on the SERS-active surfaces. In addition to these markers, we monitored changes related to amino acid residue bands for each temperature during the stability tests and thermal cycling. The spectral changes were associated with water loss and the reorganization of molecules near the nanostructured plasmonic surface, indicating saliva&apos;s sensitivity to temperature conditions. Our findings emphasize the importance of maintaining proper storage conditions for saliva films on large-area substrates to preserve sample integrity and prevent the misinterpretation of temperature-induced spectral changes. This study contributes to best practices for SERS analysis of thermally sensitive materials, particularly biofluids, especially in the context of medical diagnostics.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10400 - Chemical sciences

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

VIBRATIONAL SPECTROSCOPY

ISSN

0924-2031

e-ISSN

1873-3697

Svazek periodika

138

Číslo periodika v rámci svazku

May

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

103788

Kód UT WoS článku

001453173300001

EID výsledku v databázi Scopus

2-s2.0-86000779063