AuNPs/C-CNF/PVA hydrogel SERS sensor for comprehensive detection of antitumor drug separation and enrichment

In clinical settings, there is a significant demand for the monitoring of therapeutic drugs. Surface-enhanced Raman spectroscopy (SERS) has shown considerable potential in the field of drug analysis. Designing SERS sensors with high sensitivity, strong stability, excellent reproducibility is a challenging and fascinating goal in the field of chemical measurement. In this study, a simple and portable AuNPs/C-CNF/PVA hydrogel SERS sensor was developed, composed of gold nanoparticles (AuNPs), carboxylated cellulose nanofibers (C-CNF) and polyvinyl alcohol (PVA). Due to the “screening” effect of the hydrogel network, it is capable of separating hydrophobic molecules from macromolecules and enabling the enrichment of hydrophilic small molecules. When used to analyze 6-thioguanine (6-TG) and methylene blue (MB) in plasma, the AuNPs/C-CNF/PVA hydrogel SERS sensor showed limit of detection (LOD) as low as 7.9 × 10 −8 M for 6-TG and 3.3 × 10 −9 M for MB. Based on this technology, in blood spiking experiments using clinical samples, the recovery rate for 6-TG ranged from 99.16 % to 103.51 %, while the recovery rate for MB ranged from 93.13 % to 101.70 %. Therefore, the AuNPs/C-CNF/PVA hydrogel SERS sensor enables ultra-sensitive, integrated detection of drugs in plasma through separation and enrichment, without the need for complex pretreatment steps. This approach holds great promise for application in clinical therapeutic drug monitoring.