Electrochemical immunosensor for Busulfan in plasma based on a competitive assay: Validation with liquid chromatography–tandem mass spectrometry method
Microchemical Journal, cilt.228, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 228
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.microc.2026.118956
- Dergi Adı: Microchemical Journal
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, Chimica, Index Islamicus, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Busulfan, Electrochemical immunosensor, Liquid chromatography–tandem mass spectrometry, Magnetic bead–based assay, Therapeutic drug monitoring
- Ankara Üniversitesi Adresli: Evet
Özet
Busulfan (BSF) is a bifunctional alkylating agent widely used in myeloablative conditioning regimens prior to hematopoietic cell transplantation, where therapeutic drug monitoring (TDM) is essential owing to its narrow therapeutic window and high interindividual pharmacokinetic variability. This study reports the development and validation of a competitive electrochemical immunosensor for the rapid and sensitive determination of BSF in human plasma, with comparison to a liquid chromatography–tandem mass spectrometry (LC–MS/MS) reference method. The immunosensor is based on carboxyl-functionalized magnetic beads coupled to screen-printed carbon electrodes and operates via an indirect competitive immunoassay format with enzymatic signal amplification via a horseradish peroxidase (HRP)/H₂O₂–hydroquinone redox system. Under optimized conditions, the platform exhibited a linear range of 100–2000 ng mL−1 (R2 = 0.995), a limit of detection of 30 ng mL−1, excellent reproducibility (RSD = 4.7%), and storage stability over 45 days, with a total assay time of approximately 30 min. Accuracy was confirmed in spiked human plasma samples with recoveries of 99–104% and RSDs below 5%. Method agreement with LC–MS/MS was assessed by Passing-Bablok regression (slope = 1.009, intercept = −8.4 ng mL−1) and Bland-Altman analysis (mean bias = −8.6 ng mL−1), confirming acceptable concordance between both methods across the full analytical range. The analytical range of the developed immunosensor fully covers the clinically relevant BSF concentration window targeted during TDM (Css 600–900 ng mL−1), supporting its compatibility with routine monitoring requirements. The proposed immunosensor represents a promising proof-of-concept system that offers complementary advantages over LC–MS/MS in terms of simplicity, reduced sample preparation, and shorter analysis time. Further validation using authentic patient plasma samples, subject to ethics committee approval, will be conducted to confirm its clinical applicability.