In his book Non-Duality: A Study in Comparative Philosophy, David Loy writes:
If philosophy in the nineteenth century became historically conscious, philosophy in the twentieth century has become self-conscious. Attention has shifted from the construction of metaphysical systems to the act of philosophizing, that is, thinking itself. This has taken a different directions in Anglo-American and continental European philosophy. The former grasps the nature of thinking more objectively, by identifying it with language, and has become sensitive to the ways in which philosophical problems arise due to the misuse of words; many problems are "dissolved" by uncovering the linguistic confusions at their root. On the continent, some phenomenology has continued the traditional pursuit of a scientific "presuppositionless" philosophy, but the influential writings of Heidegger, Jaspers, and more recently Gadamer and Derrida, have shifted attention to the "subjective" act of thinking itself. Their continually evolving work may best be understood as "process philosophies" of philosophizing rather than the construction of systems that offer something objectively fixed; their most important insights concern the nature of philosophical reflection as such.
Much later in the book, Loy says "The purpose of this section has been to show that, although Derrida's differance constitutes a major philosophical insight, his employment of it does not develop its most radical implications."
Now, based on the above, if your question is interpreted as "Do modern continental philosophies act as a counter-weight or counter-argument to modern Anglo-American philosophies in the same way that the ancient sophists may have made counter-arguments to Plato?" then I would say yes. If you are, on the other hand, saying that post-modernism consists of specious arguments, as sophism has come to mean, then I would say no.