Monitoring reaction progress?
Slightly askew of what was asked, but still relevant.  TLC is not dependent on conjugation.  That reasoning suggests to me You are using UV light to visualize the TLC.  UV light is used because it is clean, quick and non-destructive.

There are destructive visualization techniques, such as vanillin stain.  In this case, after elution one dips the tlc slide into the stain, and then bakes the coated slide, and various compounds appear in vivid colours, that are normally somewhat related to the functional groups present in the molecules.  Myriad stains exist, vanillin was just my favorite when I was practicing.


(picture taken from http://www.ochemonline.com/images/thumb/5/5d/Tlc_stains.JPG/1000px-Tlc_stains.JPG)

These stains are not quite as clean or quick as UV visualization, but are still quite convenient.  There are other monitoring techniques, but nothing beats TLC for generality, cost and speed.