腦源性神經滋養因子(Brain-derived neurotrophic factor, BDNF)是神經滋養因子的一種，除影響神經細胞發育、存活之外，並在記憶和認知功能中扮演重要角色。近年來發現，BDNF蛋白和憂鬱症及失智症有關。研究中顯示高BDNF蛋白表現可協助老年人對抗阿茲海默症，低BDNF蛋白表現被認為是阿茲海默症的前兆之一。BDNF表現量降低可能是因為神經退化性疾病患者腦內環境惡化，導致內皮細胞、神經膠細胞和分泌BDNF的神經細胞受到損傷。因此BDNF蛋白可用於預測未來失智症和憂鬱症的生物標誌。^1,2,3

“磁量” BDNF蛋白免疫磁減量檢測試劑是利用免疫磁減量平台來定量BDNF蛋白濃度。BDNF蛋白抗體接合於直徑約50 nm的氧化鐵磁性奈米顆粒表面。當磁性奈米顆粒表面的抗體與BDNF蛋白結合後，磁性奈米顆粒會聚集成較大的分子，磁性奈米顆粒在外加交流磁場下產生的磁導率會因此減少。透過磁導率變化的量測，可以測得BDNF蛋白濃度。

References

1. Xie B, Zhou H, Liu W, Yu W, Liu Z, Jiang L, Zhang R, Cui D, Shi Z, Xu S. Evaluation of the diagnostic value of peripheral BDNF levels for Alzheimer's disease and mild cognitive impairment: results of a meta-analysis. Int J Neurosci. 2020 Mar;130(3):218-230.
2. Laske C, Stransky E, Leyhe T, Eschweiler GW, Wittorf A, Richartz E, Bartels M, Buchkremer G, Schott K. Stage-dependent BDNF serum concentrations in Alzheimer's disease. J Neural Transm (Vienna). 2006 Sep;113(9):1217-24
3. Ng TKS, Ho CSH, Tam WWS, Kua EH, Ho RC. Decreased Serum Brain-Derived Neurotrophic Factor (BDNF) Levels in Patients with Alzheimer's Disease (AD): A Systematic Review and Meta-Analysis. Int J Mol Sci. 2019 Jan 10;20(2):257..
4. C.C. Yang, S.Y. Yang, C. S. Ho, et al., "Development of antibody functionalized magnetic nanoparticles for the immunoassay of carcinoembryonic antigen: a feasibility study for clinical use" J Nanobiotechnology. 12: 44. 2014.