High-density micro-well array with aptamer-silver conjugates for cell sorting and imaging at single cells

Highlights: • The aptamer-silver conjugates can effectively capture cells and amplify signal. • The well-designed chip eliminates the non-specific adsorption and enhance specificity. • Different cells can be detected simultaneously if different aptamers were applied. • The captured cells can be easily localized and analyzed at the same time. -- Abstract: Characterizing cell behavior is important to modern medical diagnoses as the changes of cell behavior are often indicators of huge diseases. In order to gain enough information about cells, developing novel methods of cell sorting and imaging is an important task. With development of micro-fabrication technologies, more advanced miniaturized devices are applied to cell research. Here, a portable and easy-to-use chip with high-density periodic micro-well array is designed and fabricated to capture target cells specifically. Combining with aptamer-silver conjugates and FAM functioned report probes, the sandwich assay was successfully applied for imaging cells. Any well of the chip is carefully designed to provide abundant information on single cells. Since there are 19,200 microwells in a single chip, more information is available. Compared to other cells, such as HEK-293, MCF-7, U₂OS and Ramos cells, the sandwich assay shows high specificity towards target cell CCRF-CEM. What's more, the applications of the chip can be further expanded to other cells imaging if suitable aptamers were selected. This high-density micro-well array of aptamer-silver conjugates is hopeful to play an important role in medical diagnosis in the future.