A cytosensor based on NiO nanoparticle-enhanced surface plasmon resonance for detection of the breast cancer cell line MCF-7

The article describes the use of a designed histidine (His)-tagged arginine-glycine-aspartic acid (RGD) peptide as a linker to bind integrin to captured cancer cells, and how to amplify the surface plasmon resonance (SPR) signal after binding of NiO nanoparticles (NiO-NPs) via the His-tag on the peptide. Specifically, breast cancer cells were captured via the interaction between human mucin (MUC-1) and a gold surface modified with a MUC-selective aptamer. The resulting cytosensor exhibits specificity and high sensitivity which is due to the enhancement of the SPR signal by NiO-NPs. The breast cancer cell line MCF-7 can be easily distinguished from normal islet beta cells by using this biosensor. Implementation of the His-tagged RGD peptide modified with NiO-NPs resulted in 20-fold enhancement of the SPR signal at the limit of detection. Hence, the actual limit of detection is lowered to 136 cells per mL. In our perception, this cytosensor has a large clinical potential in that it may also be used to detect various other kinds of tumor cells.