How to determine whether a semantic concept is present in a string
This is essentially information retrieval: usually there is a collection of documents and the goal is to find the document which is the most similar to a given query (what you call the &quot;semantic concept&quot;).
The traditional way to do that is to convert the collection of documents as vectors, typically with TFIDF weight but there are many options (I assume that recent approaches favor using word (or document) embeddings). Then a similarity measure (for example cosine) is used to measure the similarity between every document and the query, and the most similar document is selected. Since in this case there would be a single document, you could use a threshold on the similarity level in order to answer yes or no (concept found or not).