Abstract

A signal-off electrochemiluminescence (ECL) biosensor was developed for the determination of specific sequence of BCR/ABL gene related to chronic myelogenous leukemia based on a mesoporous gold nanoparticle (AuNP)-luminol-silica nanocomposite and the catalytic effect of ferrocene on luminol ECL. Luminol and silica were electrodeposited on the electrode surface and AuNP was deposited on the luminol-silica hybrid film to form the AuNP-luminol-silica nanocomposite film. The AuNP-luminol-silica nanocomposite on the surface provided stable ECL. Ferrocene labeled molecular beacon (Fc-MB) was assembled onto the surface of AuNP-luminol-silica nanocomposite through Au–S bond. After the hybridization of molecular beacon with target DNA, the opening of the stem of Fc-MB caused ferrocene to be away from the electrode surface, which resulted in the decrease of ECL intensity. Accordingly, a signal-off ECL DNA biosensor was developed based on the linear relationship between the reduced ECL intensity and the concentration of the target DNA. Under the selected conditions, the ECL intensity decreased linearly with the logarithm of the concentration of target DNA from 1.0 × 10⁻¹⁵ to 1.0 × 10⁻⁹mol/L with a detection limit of 4.6 × 10⁻¹⁶mol/L.

摘要

基于介孔金纳米粒子（AuNP）-鲁米诺-二氧化硅纳米复合材料以及二茂铁对鲁米诺 ECL 的催化作用，开发了一种用于测定慢性粒细胞白血病相关 BCR/ABL 基因特异性序列的信号关闭电化学发光（ECL）生物传感器。 . 将鲁米诺和二氧化硅电沉积在电极表面，将AuNP沉积在鲁米诺-二氧化硅杂化膜上，形成AuNP-鲁米诺-二氧化硅纳米复合膜。表面上的AuNP-鲁米诺-二氧化硅纳米复合材料提供了稳定的ECL。二茂铁标记的分子信标（Fc-MB）通过Au-S键组装到AuNP-鲁米诺-二氧化硅纳米复合材料的表面。分子信标与靶 DNA 杂交后，Fc-MB 茎的打开导致二茂铁远离电极表面，这导致 ECL 强度降低。因此，基于降低的 ECL 强度与靶 DNA 浓度之间的线性关系，开发了一种信号关闭 ECL DNA 生物传感器。在选定的条件下，ECL 强度随着目标 DNA 浓度的对数从 1.0 × 10^-15至 1.0 × 10 ^-9 mol/L，检测限为 4.6 × 10 ^-16 mol/L。