Aptamer-modified magnetic SERS substrate for label-based determination of cardiac troponin I

• Published in: Mikrochimica acta (1966) 2022-01, Vol.189 (1), p.22-22, Article 22
• Main Authors: Lin, Chubing, Li, Lijun, Feng, Jun, Zhang, Yan, Lin, Xin, Guo, Heyuanxi, Li, Rui
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Aptamers, Nucleotide - chemistry; Bimetals; Biosensing Techniques - methods; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; DNA - chemistry; Gold; Gold - chemistry; Humans; Iron oxides; Limit of Detection; Magnetic Phenomena; Magnetite Nanoparticles - chemistry; Microengineering; Nanochemistry; Nanoparticles; Nanotechnology; Original Paper; Rosaniline Dyes - chemistry; Silver; Silver - chemistry; Spectrum Analysis, Raman - methods; Substrates; Troponin I - blood; Troponin I - chemistry
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-021-05121-4

A sensitive label-based SERS strategy composed of magnetic bimetallic nanoparticles Fe 3 O 4 @Ag@Au, specific aptamer, and Bradford method was developed for the quantitative determination of cardiac troponin I (cTnI) in human serum. The prepared substrate with high magnetic character, signal enhancement, and uniformity exhibited significant Raman response. After the substrate was bound to the aptamer, the target protein cTnI was specifically captured, and it showed the Raman signal when the signal reporter Coomassie Brilliant Blue G-250 (CBBG) was supplied. The Raman signal intensity at 1621 cm −1 showed a wide linear relationship with the log value of the cTnI concentration in the range 0.01 to 100 ng·mL −1 , and the estimated limit of detection (LOD) was 5.50 pg·mL −1 . The recovery and relative standard deviation (RSD) of the spike experiment in human serum samples were 92–115% and 7.4–12.7%, respectively. Graphical abstract