SERS substrates based on rose petal replicas for the oxidative stress detection

Oxidative stress leads to multiple changes in properties of cells and of biological liquids that can cause various pathologies including cardiovascular and metabolic diseases. Modern test systems make it possible to assess the concentration of oxidized molecules in the blood plasma, but do not provide direct information about oxidation of cell membranes. In this work, we presented an effective, scalable, and inexpensive technique for manufacturing biomimetic SERS sensors for the detection of biomembrane oxidation. The main feature of this technique is the use of rose petals as templates for scalable manufacturing of SERS substrates with a cavity structure that promotes the capture and immobilization of blood cells on the grooved inner surfaces of microcavities. To obtain the SERS effect in these microcavities, the silicone replicas of rose petals were covered with an Au thin film (100 nm) and spherical Au nanoparticles by the sequential deposition and annealing processes. The application of SERS substrates with a cavity structure enables to perform studies on individual erythrocytes and detect first signs of their membrane oxidation, which can be used for early diagnostics of various blood and metabolic diseases.