Miniature multi-channel SPR instrument for methotrexate monitoring in clinical samples

• Published in: Biosensors & bioelectronics Vol. 64; pp. 664 - 670
• Main Authors: Zhao, Sandy Shuo, Bukar, Natalia, Toulouse, Jacynthe L., Pelechacz, Daniel, Robitaille, Robert, Pelletier, Joelle N., Masson, Jean-François
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.02.2015
• Subjects: Antimetabolites, Antineoplastic - blood; Antimetabolites, Antineoplastic - chemistry; Biosensors; Calibration; Complex Mixtures - analysis; Complex Mixtures - chemistry; Drug Monitoring - instrumentation; Dynamic range; Dynamical systems; Equipment Design; Equipment Failure Analysis; Gold nanoparticles; Hospitals; Lighting - instrumentation; Localized surface plasmon resonance; Methotrexate; Methotrexate - blood; Methotrexate - chemistry; Miniaturization; Monitoring; Sensors; Surface plasmon resonance; Surface Plasmon Resonance - instrumentation; Therapeutic drug monitoring; Therapeutic drug monitoring; Surface plasmon resonance; Biosensors; Localized surface plasmon resonance; Methotrexate; Gold nanoparticles
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2014.09.082

A multi-channel fully integrated SPR biosensor was applied for the analysis of an anti-cancer drug, methotrexate (MTX) as a potential analytical tool used in clinical chemistry laboratories for therapeutic drug monitoring (TDM). MTX concentrations in a patient's serum undergoing chemotherapy treatments can be determined by surface plasmon resonance (SPR) sensing using folic acid-functionalized gold nanoparticles (FA-AuNP) in competition with MTX for the bioreceptor, human dihydrofolate reductase (hDHFR) immobilized on the SPR sensor chip. To validate this biosensor, 13nm FA-AuNP were shown to interact with immobilized hDHFR in the absence of MTX and this interaction was inhibited in the presence of MTX. The sensor was calibrated for MTX in phosphate buffer at different dynamic range by varying nanoparticle sizes (5, 13, 23nm) and by modifying the Kd of the bioreceptor using wild-type and mutant hDHFR. Furthermore, initial binding rate data analyzes demonstrated quantitative and fast sensor response under 60s. This MTX assay was subsequently adapted to a fully integrated multi-channel SPR system built in-house and calibrated in human serum with a dynamic range of 28–500nM. The SPR system was applied to analyzes of actual clinical samples and the results are in good agreement with fluorescence polarization immunoassay (FPIA) and LC–MS/MS. Finally, the prototype system was tested by potential clinical users in a hospital setting at the biochemistry laboratory of a Montreal hospital (Hôpital Maisonneuve-Rosemont). •Portable four channel SPR instrument powered by USB from small laptop computer.•SPR sensor for MTX in serum sample of patients undergoing chemotherapy.•Optimization of AuNP and hDHFR receptor for low detection limit.•Comparative study with FPIA and LC–MS/MS.