.png){kind=icon}
.png){kind=icon}
Return
Citrullinated Protein Sensing via Rhodamine Phenylglyoxal and Surface-Enhanced Raman Spectroscopy on Droplet-Retentive Hydrophobic Substrates
.png){kind=icon}
OA
AI
W
Y
W
K
M
C
C
DOI：10.1021/acsanm.6c01420.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
Citrullination is a post-translational modification catalyzed by peptidylarginine deiminases (PADs) and is closely associated with autoimmune diseases, cancers, and neutrophil extracellular trap-related inflammatory conditions. Although mass spectrometry, antibody-based assays, and chemical probes have been widely used to detect citrullination, each approach has practical limitations. Mass spectrometry provides high molecular specificity but requires complex instrumentation and sample preparation, whereas conventional antibody-based assays are experimentally accessible but their performance depends strongly on antibody specificity, assay configuration, and signal readout strategy. In this study, we present a surface-enhanced Raman spectroscopy (SERS)-based platform for detecting citrullinated proteins using citrullinated histone H3 (CitH3) as a representative target. Rather than relying solely on antibody recognition, the platform integrates rhodamine phenylglyoxal (Rh-PG)-mediated Raman labeling, F95 antibody-conjugated silver nanoparticles (AgNP-F95), and droplet-retentive hydrophobic SU-8 nanopillar substrates. In this design, Rh-PG serves as both a citrullination-reactive chemical probe and a Raman-active molecular reporter, AgNP-F95 conjugates provide antibody-mediated capture and local plasmonic enhancement, and the hydrophobic nanopillar substrate promotes localized enrichment during droplet evaporation. The SERS response of Rh-PG was first characterized, yielding a limit of detection (LOD) of 2.0 × 10–13 M. For targeted CitH3 detection, Rh-PG-labeled CitH3 was captured by AgNP-F95 conjugates, giving an LOD of 3.9 × 10–11 g/mL and a broad log–log linear calibration range spanning 5 orders of magnitude. The assay also showed clear selectivity for CitH3 over noncitrullinated histone H3, suggesting that nonspecific protein adsorption did not generate apparent false-positive Rh-PG signals under the tested conditions. The achieved detection limit falls within reported clinically relevant CitH3 concentration ranges in sepsis-related conditions, supporting the potential relevance of this platform for sensitive biomarker monitoring. These results demonstrate that integrating chemoselective Raman labeling, antibody-mediated capture, and evaporation-driven SERS enrichment provides a sensitive and selective hybrid strategy for detecting citrullinated protein biomarkers.
Keywords:
Biopolymers
Hydrophobicity
Metal nanoparticles
Peptides and proteins
Raman spectroscopy
citrullination
citrullinated histone H3
rhodamine phenylglyoxal
droplet-retentive hydrophobic surface
rose-petal-like wetting
surface-enhanced Raman spectroscopy
silver nanoparticles
Journal
IF:
5.5
Papers:
2.5K
Citations:
5.0W
Organization
Cited Papers