Development of a monoclonal antibody-based enzyme-linked immunosorbent assay for the analysis of 6-benzylaminopurine and its ribose adduct in bean sprouts

• Published in: Food chemistry 2016-09, Vol.207, p.233-238
• Main Authors: Zhang, Wei, He, Lishan, Zhang, Rui, Guo, Suqin, Yue, Huanfang, Ning, Xiangxue, Tan, Guiyu, Li, Qing X., Wang, Baomin
• Format: Article
• Language: English
• Subjects: 6-Benzylaminopurine; ELISA; Food safety; Monoclonal antibody; Plant growth regulator
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2016.03.103

•This is the first paper on mAb-based icELISA for 6-BA in bean sprouts.•6-BAR was confirmed by LC–ESI-MS as a metabolite of 6-BA in bean sprouts.•The icELISA could sensitively detect 6-BAR, as a potential biomarker.•The icELISA offers an advantage for detecting trace level of 6-BA in bean sprouts. 6-Benzylaminopurine (6-BA), a cytokinin plant growth regulator, has been banned for use in bean sprout production in China. An indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed with a specific monoclonal antibody (mAb 3E5). The assay showed a half-maximum inhibition concentration (IC50) and detection range of 18.9ng/mL and 3.6–106ng/mL, respectively. Recoveries of 6-BA spiked in home cultured bean sprout samples averaged from 75% to 89% with a correlation coefficient (R2) of 0.998 between the results determined by icELISA and those by liquid chromatography–electrospray ionization quadrupole Orbitrap mass spectrometry (LC–ESI-MS). LC–ESI-MS showed that 6-BA had been partially metabolized to 6-benzylaminopurine riboside (6-BAR) in the positive samples. The content of 6-BA determined by icELISA was about 5–70 times higher than that of LC–ESI-MS because mAb 3E5 had 315% cross-reactivity with 6-BAR. Such icELISA being ultra-sensitive to 6-BAR would allow quick monitoring of 6-BA by detecting 6-BAR as a potential biomarker.