Peptide-Coated Bacteriorhodopsin-Based Photoelectric Biosensor for Detecting Rheumatoid Arthritis

• Published in: Biosensors (Basel) 2023-10, Vol.13 (10), p.929
• Main Authors: Chen, Hsiu-Mei, Tsai, Yi-Hsuan, Hsu, Chien-Yi, Wang, Yong-Yi, Hsieh, Cheng-En, Chen, Jin-Hua, Chang, Yu-Sheng, Lin, Ching-Yu
• Format: Article
• Language: English
• Subjects: Antibodies; Arthritis; Atomic force microscopy; Autoantibodies; Bacteriorhodopsin; Biomarkers; Biosensors; Citrulline; Coated electrodes; Coatings; Design and construction; Diabetes; Diagnosis; Electrodes; Enzyme-linked immunosorbent assay; Fourier transforms; Gold; Graphene; Health aspects; Immunoglobulin A; Nanoparticles; peptide; Peptides; photoelectric biosensor; Photoelectric effect; Photoelectric emission; Photoelectricity; Polyethylene glycol; purple membrane; Purple membranes; Reduction; Reynolds number; Rheumatoid arthritis; Rheumatology; Sensors; Spectrum analysis; Substrates; Trypsin; Trypsin inhibitors
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios13100929

An effective early diagnosis is important for rheumatoid arthritis (RA) management. This study reveals a novel RA detection method using bacteriorhodopsin as a photoelectric transducer, a light-driven proton pump in purple membranes (PMs). It was devised by covalently conjugating a PM monolayer-coated electrode with a citrullinated-inter-alpha-trypsin inhibitor heavy chain 3 (ITIH3)542–556 peptide that recognizes the serum RA-associated autoantibodies. The direct serum coating decreased the photocurrents in the biosensor, with the reduction in the photocurrent caused by coating with an RA-patient serum that is significantly larger than that with a healthy-control serum (38.1% vs. 20.2%). The difference in the reduction in the photocurrent between those two serum groups widened after the serum-coated biosensor was further labeled with gold nanoparticle (AuNP)-conjugated anti-IgA (anti-IgA-AuNP) (53.6% vs. 30.6%). Both atomic force microscopic (AFM) and Raman analyses confirmed the sequential peptide, serum, and anti-IgA-AuNP coatings on the PM-coated substrates. The reductions in the photocurrent measured in both the serum and anti-IgA-AuNPs coating steps correlated well with the results using commercial enzyme-linked immunosorbent assay kits (Spearman rho = 0.805 and 0.787, respectively), with both a sensitivity and specificity close to 100% in both steps. It was shown that an RA diagnosis can be performed in either a single- or two-step mode using the developed biosensor.