nano particles in order to quantify the sers enhancement a neat solution of thiophenol is used for recording the raman spectra and a 1 mm solution is used for sers measurements fig4 a and b shows the raman and sers spectra of thiophenol tp the raman enhancement factor or gain is calculated for the 1080 cm u2212 1 band of tp using the standard method and found to be of the order 10 6 other molecules such as nucleic acid bases different dye molecules proteins and small molecules were detected at low concentrations using this instrument one of the most important aspects of the raman instrumentation for sers studies on bio molecules is the ability to perform experiments in aqueous phase for which one uses a water immersion objective lens in order to obtain high spatial resolution high throughput and tight focusing of the incident beam in sers studies it is necessary to use a high na and a high magnification objective lens like the 1 2 na and 60 u00d7 magnification lens used in the present experiment this has been a common approach for single molecule sers experiments as well as confocal raman imaging through a simple experiment in the instant invention the ability to spatially resolve two regions inside the aqueous solution along the focusing direction which are separated by only a few micrometers this reveals two important aspects namely.