Insulin is one of the most important protein hormones that is
synthesized by pancreatic b-cells and regulates the metabolism of
glucose in the blood [1]. Diabetes is a group of chronic diseases that
is caused by the insufficient release of insulin or loss of insulin
action at target tissues, which results in aberrant glucose and lipid
metabolism. Because of the central role of insulin in diabetes,
development of efficient analytical methodologies for direct
detection of it in blood is one of the clinical exigencies for diagnosis
of diabetes. Three main procedures have been reported for the
determination of insulin: bioassays [2], immunoassay [3], and
chromatographic methods [4]. In general, the bioassay systems
cannot be used by routine clinical laboratories because they are
relatively insensitive and imprecise [