Conventional approaches for treating tumors encompass chemotherapy, radiotherapy, and surgery. However, these methods come with their limitations when applied in clinical practice. Aptamers are often referred to as “chemical antibodies” and consist of short DNA or RNA molecules, designed to bind to a wide range of targets, including proteins or nucleic acid structures. They exhibit strong affinities and remarkable specificity for their target molecules, making them capable of functioning as therapeutic agents to directly impede tumor cell proliferation. This approach helps minimize the harm to normal cells, thus reducing toxicity through decreased side effects. Here we report the procedure to develop ssDNA aptamer and investigate its ability to inhibit cancer cell proliferation in HeLa and MCF-7 cancer cell lines.