请帮忙翻译这段文字QD-Protein Conjugate Preparation. Bioconjugate complexes were prepared by adding appropriate amounts of Cy3-labeled and unlabeled MBP to 100,uL of 10 mM sodium tetraborate buffer solution (pH 9). Approximately 24 pmol of D... 请帮忙翻译这段文字QD-Protein Conjugate Preparation. Bioconjugate complexes were prepared by adding appropriate amounts of Cy3-labeled and unlabeled MBP to 100,uL of 10 mM sodium tetraborate buffer solution (pH 9). Approximately 24 pmol of DHLA capped QDs were added to the MBP solution and allowed to self-assemble for ~15 min at room temperature. Molar ratios of MBP-Cy3 to QDs were discretely varied among samples from 0 to 10 while the overall ratio of MBP (labeled and unlabeled) to QD was maintained at 15 (see sketch in Figure 1). The individual samples were then diluted with sodium tetraborate buffer to a total volume of 3 mL. The solutions were placed in a 10 mm optical path quartz fluorescence cuvette (FUV, Spectrocell, Oreland, PA), and the emission spectra were measured using a SPEX Fluorolog-2 fluorimeter (Jobin Yvon/SPEX, Edison, New Jersey). All samples were excited at 430 nm, which is near the minimum of the Cy3 absorption spectrum in order to reduce interference from direct excitation of the acceptor (see Figure 2).
Furthermore, control spectra collected from MBP-Cy3 conjugates in the absence of QD donors were recorded and subtracted from the solution spectra to adjust for dye emission exclusively due to direct excitation. To avoid inner filtering effects, QD conjugate preparations with optical density (OD) at the excitation line below 0.05 were used in all experiments.
量子点-蛋白交联制备。在100微升的10mM四硼酸钠缓冲液(pH 9)中加入适量Cy3标记的和未标记的MBP制备成生物交联配合物。约24 pmol的DHLA封顶量子点被添加到MBP溶液,并在室温下自体组装~15分钟。MBP-Cy3相对于量子点的摩尔比在不同样品中有从0到10的离散变化,而MBP(标记和未标记)对量子点的整体比例维持在15(参见图1)。然后每个样品用四硼酸钠缓冲液稀释至3毫升的总体积。稀释后的溶液被放置在一个10毫米的石英荧光比色皿光程(远紫外,Spectrocell,Oreland,宾夕法尼亚州),发射光谱测量采用SPEX Fluorolog-2荧光计(Jobin Yvon公司/ SPEX仪,Edison,新泽西州)。所有样品的激发均在430 nm,此波长接近Cy3吸收光谱Z低点以便减少受主直接激发造成的干扰(见图2)。
此外,从溶液光谱中减去了MBP-Cy3结合物在没有量子点施主时记录的控制谱,以消除直接激发产生的染料发射造成的影响。为了避免内部过滤效应,所有实验的量子点交联制备都用了激发线在0.05以下的光密度(OD)。