The possibilities provided by aptamers are enormous, and some aptamers have already shown many important applications in bioanalysisand biomedicine [20] [21] [22] [23] . Particularly, several aptamers have been generated against cancer-related proteins, such as PDGF, VEGF, HER3, NFkB, tenascin-C, or PMSA [24] [25] [26] . Many aptameric sensors, probes and assays have been developed to allow sensitive and selective detection of these cancer biomarker proteins [27] . For instance, Yang et al has reported a lightswitching excimer aptamer probes for sensitive quantitative detection of PDGF in cell media [28] . Kwon et al have developed a functionalized polypyrrole nanotube with aptamer to build a VEGF biosensor [29] . Aptamers have also been applied for molecular imaging to in vivo characterize the complex pathogenic activities that accompany tumor growth for disease early diagnosis and pathogenesis measurement [30] [31] [32] [33] . Since the targets for aptamers could be intracellular, extracellular or cell-surface biomolecules, various therapeutic methods have been developed using the aptamers as targeting reagents [34] [35] [36] [37] , which greatly broaden the range of targeted therapy. In addition, some therapeutically useful aptamers have been found to inhibit protein-protein interactions, such as receptor-ligand interactions, and thereby function as antagonists [38] .