The analytical methods which are currently used for studying kinetics of different physical, chemical and biological processes have many limitations : most methods work for only specific types of materials; sample preparation often demand multiple and complex steps to be followed; real time, in situ tracking of a process continues to remains a challenge; importantly most methods are found inadequate when the event happens at a location that is not easily accessible to direct measurement. To overcome these limitations, we have demonstrated here the application of Elastocapillary effect , which is essentially based on measurement of deformation of a soft solid, that occurs because of change in interfacial energy of a solid-liquid interface. Elastocapillary effect, in a moderately soft material, generates miniscule deformation that is not measurable by simple methods . We have, however, adopted here a specific geometry that leads to large enough deformation that can be tracked using optical profilometry . In essence, the process occurs within the confines of a micro-channel embedded inside a soft PDMS layer, at the vicinity of the channel surface. This process either leads to generation of a new chemical species or adsorption of one, on it. Both these effects result in dynamic alteration in interfacial energy and consequent change in deformation of the thin wall of the channel which is monitored using optical profilometry. As an example, we employed the elastocapillary effect to estimate the rate constant for a surface reaction leading to evolution of Gold and Silver nanoparticles, which matched well with that from UV-vis spectrophotometry.