A Novel GABABR1a Receptor Electrochemical Biosensor Based on Gold Nanoparticles Chitosan-horseradish Peroxidase

A novel gamma aminobutyric acid type B receptor subunit 1a (GABA_BR1a) biosensor modified with double-layer gold has been developed for the first time. In this work, the synthesized plasmid was transfected into HEK-293T cells by liposome transfection, and the target protein GABA_BR1a was obtained. The horseradish peroxidase was used as a signal amplification system to produce a double-layer gold modified GABA_BR1a receptor biosensor. The ligand gamma aminobutyric acid (GABA), jujuboside A and baclofen were detected by the time-current method with the biosensor. The results showed that the action regularity of GABA, jujuboside A, and baclofen on GABA_BR1a receptor was fitted with hyperbolic fitting (R² was 0.9740, 0.9770 and 0.9770, respectively). The double reciprocal method was used to figure out the affinity constant (K_a) of GABA, jujuboside A, and baclofen with the receptor, i. e. 2.1016×10⁻¹⁵ mol/L, 1.7601×10⁻¹⁴ mol/L, and 1.633×10⁻¹⁴ mol/L, respectively, indicating that these measured compounds exhibited different action strength on the receptor. Based on the above, this study will provide a basis for drug screening and will also provide a new idea and method for investigating quantitatively the interaction between receptors and ligands in the future.