Diabetes mellitus, which is characterized by the defective regulation of blood glucose, is the most common disorder of the endocrine system, affecting 25.8 million people in the United States alone (2010). Given the lack of suitable therapeutic options, effective glycemic control is imperative in avoiding acute and chronic complications such as diabetic coma, and microvascular and macrovascular complications. To this end, several research groups, including our own laboratory, have pursued the development of a noninvasive blood glucose sensor, using a wide variety of optical and spectroscopic modalities. Nevertheless, these attempts to monitor glucose levels directly through Raman, infrared or other optical modalities have faced significant challenges and none have been translated to clinical practice. Given this scenario, glycated hemoglobin (HbA1c) presents a new promising target for performing long%term diabetes monitoring. While monitoring blood glucose remains the gold standard for continuous monitoring and evaluation of treatment options, HbA1c has gained approval in the medical community in assessing the long%term history of glycemic control. HbA1c is formed by the nonenzymatic glycosylation (glycation) of hemoglobin exposed to blood glucose and therefore has a strong correlation with the average glucose concentrations in the bloodstream in the preceding three-month period (life span of the erythrocytes). Because of this strong correlation, HbA1c levels have been regularly used to monitor long-term glucose control in established diabetics and has been recently approved for screening for diabetes (HbA1c ≥ 6.5%) and prediabetes (5.7% ≤ HbA1c ≤ 6.4%) in the United States.