This is nicely composed, with the main visual elements positioned well. A good level of detail, too. But I do find the burned out white spot in the background a bit distracting.
I'll take your word for it that the door knob is glass. But there's not a lot of "glassy" things happening, in terms of interesting reflection, refraction, etc.
I think this could have been an interesting subject, but you didn't do much with it. If you could get some light or some color working with it, or introduce a person (child) using the knob it would have helped the shot a lot.
the light on the right is distracting. otherwise, nice capture of the texture of the paint on door. The door itself is interesting...layers of paint and brush strokes.
I think that a different POV may have helped this image. The pattern in the glass is fairly interesting, but because door nobs are so common, I think it would be hard to get a really captivating image of one.
This picture is nice and sharp and all, but, dare I say it, I think it lacks interest. Just my own opinion of course and I don't know why I think this cos there are a lot more less interesting subjects that have been photographed in a more interesting way. Maybe if the light was more directional or/and the area on the right was darker to make it look more abstract.