"serve as a barrier" is grammatically correct and can be used in written English.
It is typically used to describe something that acts as an obstacle or hindrance to something else. Example: The Great Wall of China serves as a barrier between China and its neighboring countries.
In 1998, a company called Z-Clip suggested that one of its livestock fences serve as a barrier.
"One of the most important functions of the skin is to serve as a barrier," she said.
"This provision is misguided and will serve as a barrier to health care for otherwise eligible United States citizens," said Gov. Chris Gregoire of Washington, a Democrat.
Well, their labor contracts, with guaranteed living wages, often serve as a barrier to the kind of restructuring deals that people like Ross want to negotiate.
These programs serve as a barrier for domestic agricultural workers while depressing wages and working conditions for the entire work force.
And, for a long time, this made me feel impossibly ashamed of her — and, later, it pushed me to learn a language that could serve as a barrier between her frenzies and me.
TJs also serve as a barrier and allow for selective molecular transportation (Hartsock and Nelson, 2008).
Some authors note that rejection of evolution can serve as a barrier to developing knowledge about it (Coburn 1994; Coburn Scharmann 1990).
As a result, these terms may serve as a barrier to accurate communication or even thought about women's experiences of sex.
The bodily exchange between mother and child can serve as a barrier to love, imprisoning the child in an overwhelming bond.
Under these conditions, the polymerization of TCA may be favored, leading to a thin film on the metal surface that appears to serve as a barrier to corrosion.
