Target cells capture and detection based on a surface plasmon resonance biosensor

A novel and effective method for target cells capture and detection is developed in a label-free and real-time mode. The cultured cell line (TZM-bl) expressed as CD4+ was used as the positive CD4+ T lymphocytes for target cells capture and detection experiments. The target cells were captured on various surfaces (such as glass, polydimethylsiloxane, and metal) based on a specific immunity method. The gold surface of the surface plasmon resonance (SPR) sensing chip modified with a nano denaturalised bovine serum albumin layer had the best capture capacity. A total of 90.9% positive CD4+ T lymphocytes were captured with a slow flow rate of 5 μl/min, whereas 84.1% of cells were kept with a fast flow rate of 2 ml/min. Furthermore, the captured positive cells on the SPR sensing chip were detected on-line by using author´s home-made SPR biosensor. From the experimental results, 75 cells/μl could produce an obvious change in the SPR response signal, which holds great potential for target cells capture, reorganisation and further analysis of CD4+ T lymphocytes in human peripheral blood.