Transmembrane Protein‐Based Electrochemical Biosensor for Adiponectin Hormone Quantification

Decreased adiponectin hormone secretion occurs 10–20 years before chronic hyperglycemia, and is a great indicator of further development of type 2 diabetes. Here, we developed an electrochemical biosensor for adiponectin quantification based on specific transmembrane receptors (AdipoR1 and AdipoR2). Under optimized conditions, cyclic‐voltammetry‐based adiponectin biosensors displayed linearity ( R 2 =0.992) in a wide range of concentrations (0.025–0.75 μmol l −1 ), including typical human serum levels, with a detection limit of 7.0 nmol L −1 and reproducibility of 1.7 %, n =3. Electrochemical impedance spectroscopy results showed a similar behavior, with a linear increase in charge‐transfer resistance ( R 2 =0.971) from 0.025 to 1.00 μmol l −1 , a detection limit of 7.0 nmol L −1 , and reproducibility of 5.6 %, n =3. Furthermore, the analytical results obtained by using the biosensor in human serum samples were in agreement with those obtained by using the enzyme‐linked immunosorbent assay (ELISA) at a 95 % confidence level. It is expected the proposed device increases the number of predictive type 2 diabetes diagnostics, promoting early treatment and patient awareness about the precautions to be taken.