Self-calibrating sensor based on S-CNF/Au NSs for the detection of malondialdehyde levels in the serum of patients with gastric cancer

Abstract Cellulose-gold nano stars 2D substrates (S-CNF/Au NSs) with outstanding homogeneity and stability were prepared. S-CNF/Au NSs were modified with PATP, and the ratio of I 1655 (the C = N bond produced by the Schiff base reaction with MDA) to I 1078 , whose intensity was almost unaffected under acidic conditions, was further ensured by self-calibration to ensure the substrate homogeneity and credibility, while ensuring the simplicity of the portable SERS instrument. The impact of the portable Raman instrument on the study due to the variation of peak intensity without the use of microscope focusing was reduced, and a linear detection range of 2.5 × 10 − 2 ~2.5 × 10 − 4 mM and a LOD of 9.14 × 10 − 11 mM were achieved. This SERS substrate also has the ability to sensitively differentiate between serum of gastric cancer patients and healthy individuals ( p < 0.0001), which is superior to colorimetric analysis ( p < 0.01).