Re: Is there something that will complex with simple sugars to show absorbance?

Dear User,

If you will search in some university library close to you,
you might find a number of books on the general title 
"Carbohydrate analysis".
There are a great number of reagents which will produce coloration
corresponding in intensity to the concentration of the carbohydrate.
Most of these reagents produce slightly different colors with different
sugars, so calibration is always ncessary.
Historically, one of the first methods is Phenol-Sulphuric acid method,
which allows one to determine up to nanomolar concentrations of carbohydrates.
It is so sensitive that one should avoid using filter paper and other 
cellulose products when preparing samples because the measurement 
would be off-set by traces of cellulose and cellulose hydrolysis products.
There are more convenient methods, but they all would require more or less
expensive reagents.
Amino carbohydrates are determined by the means of Elson-Morgan reaction
(Biochem. J., 1933, #27, 1824), and other reactions (such as ninhydrin e.g)
In general, I strongly advise you to research in the literature; any decent
book on analytical chemistry would suggest a number of ways to
determine carbohydrates colorimetrically.
Write me if you need more help.

A.G.E.