School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, 637457, Singapore.
School of Biological Science, Nanyang Technological University, Singapore, 637551, Singapore.
Angew Chem Int Ed Engl. 2019 Apr 1;58(15):4983-4987. doi: 10.1002/anie.201900092. Epub 2019 Feb 20.
The detection of exosomes is promising for the early diagnosis of cancer. However, the development of suitable optical sensors remains challenging. We have developed the first luminescent nanosensor for the multiplex differentiation of cancer exosomes that bypasses real-time light excitation. The sensor is composed of a near-infrared semiconducting polyelectrolyte (ASPN) that forms a complex with a quencher-tagged aptamer. The afterglow signal of the nanocomplex (ASPNC), being initially quenched, is turned on in the presence of aptamer-targeted exosomes. Because detection of the afterglow takes place after the excitation, background signals are minimized, leading to an improved limit of detection that is nearly two orders of magnitude lower than that of fluorescence detection in cell culture media. Also, ASPNC can be easily tailored to detect different exosomal proteins by changing the aptamer sequence. This enables an orthogonal analysis of multiple exosome samples, potentially permitting an accurate identification of the cellular origin of exosomes for cancer diagnosis.
外泌体的检测有望用于癌症的早期诊断。然而，开发合适的光学传感器仍然具有挑战性。我们已经开发出了第一个用于多重区分癌症外泌体的发光纳米传感器，该传感器无需实时光激发。该传感器由近红外半导体聚合物（ASPN）组成，它与带有猝灭剂标记的适体形成复合物。纳米复合物（ASPNC）的余晖信号最初被猝灭，在存在适体靶向的外泌体时被打开。由于检测是在激发之后进行的，因此背景信号最小化，导致检测限提高了近两个数量级，比细胞培养基中的荧光检测低得多。此外，通过改变适体序列，ASPNC 可以很容易地被定制为检测不同的外泌体蛋白。这使得对多个外泌体样本进行正交分析成为可能，有可能为癌症诊断提供对外泌体细胞来源的准确识别。
