Simultaneous determination of insulin and glucose in human serum based on dual emissive fluorescent nano-aptasensor of carbon dots and CdTe/CdS/ZnS quantum dots.

• A dual emissive fluorescent nano aptasensor of CDs and CdTe/CdS/ZnS QDs was designed for simultaneous detection of human serum glucose and insulin levels. • All the reaction parameters were optimized and a polynomial regression model was constructed to explain the effects of reaction parameters. • The probe was validated and applied successfully to the determination of the stated analytes in human serum. A dual emissive fluorescent nano aptasensor was designed for simultaneous detection of human serum glucose and insulin levels. CdTe/CdS/ZnS quantum dots and carbon dots were synthesized and conjugated with the aptamers of glucose and insulin, respectively. The fluorescence of these conjugates was quenched by nano-graphite based on the static quenching and inner filter effect, and restored on the addition of the analytes. All reaction parameters were optimized using analysis of variance, and a polynomial regression model was constructed and verified to explain the effects of reaction parameters on the outcome. The linear ranges of insulin and glucose were 0.2–2 nM and 0.5–7 mM, respectively. The limits of detection for insulin and glucose were 0.018 nM and 0.058 mM, respectively. All the values of relative error % were within the range of −5.00−4.00%, and the values of relative standard deviation % were ≤3.77%. The changes in fluorescence intensity restoration of the probe in the presence of various interfering species were less than 5%, and all the recoveries for glucose and insulin were in the range of 90–110%. The probe was validated and applied successfully to the determination of the stated analytes in human serum. The fabricated aptasensor can be used to diagnose diabetes and its type with a single assay in clinical diagnostic labs. [ABSTRACT FROM AUTHOR]