Laboratory of Controllable Preparation and Application of Nanomaterials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, and Graduate University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Biosens Bioelectron. 2011 Apr 15;26(8):3488-93. doi: 10.1016/j.bios.2011.01.031. Epub 2011 Feb 2.
Biomolecules detection by size-controlled quantum dots (QDs) was promising in developing clinic diagnostic techniques. In this work, a novel bioanalytical platform was developed to detect the activity of nicotinamide adenine dinucleotide (NAD) dependent enzyme, lactate dehydrogenase (LDH), and the concentration of glucose by the changes of fluorescence intensities of the QDs based on the electron transfer between QDs and sensitive biomolecules. The fluorescence intensities of the QDs was firstly quenched by NAD and then intensified with increasing amounts of the LDH because of the consumption of the NAD by the biocatalyzed reaction. Also the glucose led to the decline of fluorescence due to the formation of hydrogen peroxide (H(2)O(2)) which was the product of the glucose reacting with the glucose oxidase (GOD). The linear calibration plots of the activity of LDH and glucose were obtained from 250 to 6000 U/L and 1.67 to 6.67 mM, respectively. The detection system was also successfully applied to detect LDH and glucose in human serum samples. This analysis process was very convenient and simple because the QDs need not to be modified by any organic or biological molecules before they were used into the system. Moreover, the established method had great potential in detection of the physiological level of some biomolecules in clinical diagnostics of various diseases.
通过控制量子点（QDs）的大小进行生物分子检测，在开发临床诊断技术方面具有广阔的前景。在这项工作中，我们开发了一种新的生物分析平台，通过基于 QDs 与敏感生物分子之间的电子转移的 QDs 荧光强度变化来检测烟酰胺腺嘌呤二核苷酸（NAD）依赖性酶、乳酸脱氢酶（LDH）的活性和葡萄糖浓度。NAD 首先猝灭 QDs 的荧光强度，然后随着生物催化反应中 NAD 的消耗，荧光强度逐渐增强。此外，由于葡萄糖与葡萄糖氧化酶（GOD）反应生成的过氧化氢（H₂O₂），导致荧光强度下降。LDH 的活性和葡萄糖的线性校准曲线分别在 250 到 6000 U/L 和 1.67 到 6.67 mM 的范围内获得。该检测系统还成功地应用于人血清样品中 LDH 和葡萄糖的检测。由于 QDs 在用于该系统之前不需要用任何有机或生物分子进行修饰，因此该分析过程非常方便和简单。此外，该方法在检测各种疾病的临床诊断中某些生物分子的生理水平方面具有很大的潜力。
