browser caching express nodejs

I'm trying to setup browser caching on my website without any success There is my code on my server.js file

app.use(fonction(req, res, next){
res.set({
    Expires: new Date(Date.now() + 2592000000).toUTCString()
});
next();
})

app.use(express.static(path.join(__dirname, '../build/public'),{maxAge:2592000000}));

Whats wrong ?

via Thargarius