Development of a SERS Probe for Selective Detection of Healthy Prostate and Malignant Prostate Cancer Cells Using ZnII

Even in the 21st century, prostate cancer remains the second leading cause of cancer-related death for men. Since a normal prostate gland has a high Zn-II content and there are huge differences in Zn-II content between healthy and malignant prostate cancer cells, mobile zinc can be used as a biomarker for prostate cancer prediction. A highly efficient surface enhanced Raman spectroscopy (SERS) probe using a p-(imidazole)azo)benzenethiol attached gold nanoparticle as a Raman reporter, which has the capability to identify prostate cancer cells based on Zn-II sensing, has been designed. A facile synthesis, characterization and evaluation of a Zn-II sensing Raman probe are described. Reported data indicate that after binding with Zn-II, Raman reporter attached to a gold nanoparticle forms an assembly structure, which allows selective detection of Zn-II even at 100ppt concentration. Theoretical full-wave finite-difference time-domain (FDTD) simulations have been used to understand the enhancement of the SERS signal. The SERS probe is highly promising for in vivo sensing of cancer, where near-IR light can be easily used to avoid tissue autofluorescence and to enhance tissue penetration depth. Reported data show that the SERS probe can distinguish metastatic cancer cells from normal prostate cells very easily with a sensitivity as low as 5 cancer cellsmL(-1). The probe can be used as a chemical toolkit for determining mobile Zn-II concentrations in biological samples.