There is no significant difference in these two types of probable cause.
In both cases, the level of proof is the same. Probable cause is a level of proof that is above mere suspicion but is much less than what is needed to convict a person. Probable cause must be based on identifiable facts that would lead a reasonable person to believe that a crime has been committed and a given person is responsible.
The evidence that supports probable cause for going to trial is likely to be more carefully scrutinized. Prosecutors will scrutinize it because they do not want to try a losing case. It will be fully scrutinized in the preliminary hearing, which is something that is not held before an officer has permission to detain a suspect.
The level of proof needed for these two, then, is not technically different. However, officers often have to detain suspects on their own initiative. They have to determine for themselves whether they have probable cause. By contrast, the presence of probable cause to go to trial is examined more carefully and by more people since a trial is a much more significant step than the simple detention of a suspect.