• The temporal behavior of theragnostic is vital to improve the efficacy in biological applications.
• Variety of nanoprobes are used as theragnostic of which plasmonic nanobiolabels have optical, photothermal and surface enhanced RS properties.
• However, due to complexity of biological environment resulting in multiple interfering molecules mislead the signals.

The aforesaid problems are eased with a combined  optical microspectroscopic technique as claimed in  present patent subject matter.

A method for the patent comprising:

1. A high resolution dark field condenser from Dark field scattering Micro- spectroscopy (DFSMS)

2. A Raman scattering Micro spectroscopy (RSMS)

• Wherein the high-resolution dark field condenser is integrated with conventional point-scan confocal RSMS set-up that utilizes light source with wavelength of 400-1000 nm to excite plasmonic modes of noble metal nanoparticles and a 532 nm laser to excite Raman spectra for colocalization of both plasmonic nanobiolabels and biomolecules in biological samples.
• The plasmonic nanobiolabels (silver and gold nanoparticles) is identified in chemical and biological nature using their inherent spectroscopic features. It is located in vicinity of Escherichia coli using SERS.
• The biomolecules include proteins, DNA and RNA molecules; the biological samples include bacteria (Escherichia coli), mammalian cells (HEK293 cells). 
• The plasmonic nanobiolabels are located in HEK293 cells and biomolecules are colocalized with them.
• The state of plasmonic nanobiolabels is identified in terms of size, shape or state as a single, dimer or aggregated particles.
• The plasmonic & Raman scattering spectroscopy is performed on chemical-biological systems.