Use req.query, for getting he value in query string parameter in the route. Refer req.query. Say if in a route, http://localhost:3000/?name=satyam you want to get value for name parameter, then your 'Get' route handler will go like this :-
app.get('/', function(req, res){
console.log(req.query.name);
res.send('Response send to client::'+req.query.name);
});