Highly sensitive vancomycin detection using a fiber-optic sensor with AuNPs/MWCNTs/DNA aptamer synergistic modification

Due to its narrow treatment window, the vancomycin concentration in the patient’s body needs to be monitored regularly to guide dose optimization and ensure safety and efficacy. Here, we developed a fiber-optic surface plasmon resonance (SPR) vancomycin sensor based on gold nanoparticles (AuNPs)/multiwalled carbon nanotubes (MWCNTs)/DNA aptamer synergistic modification. AuNPs can effectively enhance the local electromagnetic field and plasmon resonance effects, while MWCNTs have a strong electronic conductivity and a high specific surface area. The synergistic effect of the two can achieve dual amplification of the SPR signal, thereby improving the sensitivity. Vancomycin aptamer can specifically capture vancomycin molecules and induce spatial conformational changes, thereby increasing the effective refractive index. Experimental results confirmed that within 30 μM–400 μM, the sensitivity of vancomycin detection is as high as 0.0527 nm/μM, and the detection limit is 18.11 μM. Moreover, the vancomycin sensor exhibits excellent stability and specificity. The vancomycin sensor is low-cost, easy to use, and has the potential to be applied for rapid and accurate determination of vancomycin in clinical settings.