Aim: Development of highly sensitive diagnostic nanoprobe for cancer imaging based on surface-enhanced Raman scattering (SERS) platform. Materials & methods: Synthesis of novel squaraine dyes as a Raman signature molecule denoted as lipoic-squaraine-lipoic (LSL), propyl-squaraine-lipoic (PSL) and propyl-squaraine-propyl (PSP). The SERS-nanotag constructed with a Raman signature molecule which is attached on gold nanoparticle and further encapsulated with heterofunctionalized PEG. Antibody conjugation with best SERS-nanotag for target specific recognition. Results: SERS nanotag Au-LSL-PEG showed significant signal intensity and remarkable stability. Anti-EGF receptor and Her2-conjugated Au-LSL-PEG-nanotag were successfully applied for selective recognition of cancer cells like A549, OSCC and MCF7. Conclusion: The newly developed SERS-nanotag Au-LSL-PEG serves as a valuable tool for diagnostic detection of cancer cells, and may find potential applications for cancer screening in real patient samples. © 2015 Future Medicine Ltd.