This investigation was aimed at assembling different genetic building blocks to produce a focused DNA sensor to detect proteins related to glucose in blood, in order to diagnose early diabetes using synthetic biology and conventional molecular biology.A glucose DNA sensor was constructed in Saccharomyces cerevisiae using genomic and synthesized sequences and were tested in both, In vivo using human blood plasma sampled, and In vitro using cultural media.The results were based on fluorescence intensity of the DNA sensor and compared with clinical methods.The DNA sensor was highly sensitive when mixed with plasma samples from different patients (i.e., diabetic, pre-diabetic, and normal) showing high fluorescence, and was able to detect a wide concentration range of glucose equivalent to clinical glycaemia values.Expression of proteins pertaining to glucose metabolism production was determined by 2D-DIGE gel electrophoresis-maldi analysis.The glucose sensor produced results less than a minute after being mixed with a drop of a human blood sample.Our results highlight the advantages of using constructed DNA sensors to detect glucose in blood for early diagnosis of diabetes.The yeast DNA glucose sensor was assembled successfully with standardized genetic parts and was able to detect low levels equivalent to clinical glycaemia (<140 mg/ dL), as well as a higher equivalent level of glycaemia (>200 mg/dL).Thus, our sensor can be used for early diagnosis of diabetes or pre-diabetic conditions, thereby allowing for earlier clinical intervention.The direct correlation between levels of glucose and the intensity of fluorescence of the DNA sensor shows the advantage of using this technology in order to identify specific types of diabetic patients.Sometimes, it is difficult to establish accurate correlations with different methods.