Police launched a major operation following the robbery outside a Lloyds TSB cash machine in St Vincent Street last night.
The force's helicopter and dozens of vehicles were involved.
It was also reported armed police were also called to the scene.
An employee of security firm G4S was robbed of what was described as a "cash cassette" at about 8pm.
Police said a man allegedly threatened a security staff member, but no one was injured in the incident.
It is not yet known how much money was taken.
The search focused on the Anderston and Finnieston areas, close to Cranstonhill police station.
It was then extended to the West End, where it was reported officers with dogs were searching an area of Dowanhill.
One local said: "I have never seen so many police in all my life.
"They taped the place off for a while and had sniffer dogs here as well."
A police spokeswoman said: "A 38-year-old man has been detained in connection with an incident last night."
CID in Partick are appealing for witnesses.