Non-enzymatic acetylcholine electrochemical biosensor based on flower-like NiAl layered double hydroxides decorated with carbon dots

Abstract

A non-enzymatic acetylcholine (ACh) electrochemical biosensor was constructed based on flower-like NiAl layered double hydroxides (NiAl-LDHs) decorated with carbon dots (CDs). The flower-like NiAl-LDHs with a cross-linking nanosheet structure and high specific surface area were hydrothermally fabricated. Then CDs with negative surface charge were decorated on the NiAl-LDHs with positively charged brucite-like layers to obtain NiAl-LDH/CD composites. Compared with the NiAl-LDHs, the NiAl-LDH/CD composites exhibited enhanced electroconductivity and electrocatalytic performance for ACh oxidation. The NiAl-LDH/CD composites modified glassy carbon electrode had a wide linear response range of 5–6885μM, high sensitivity of 133.20±0.03mAM−1cm−2 and low limit of detection of 1.7μM, which are superior among the non-enzymatic ACh electrochemical biosensors. The biosensor also exhibited a good durability and long-term stability, and an excellent selectivity for ACh detection. The good performance in the non-enzymatic detection of ACh could be attributed to the synergistic effect between NiAl-LDHs and CDs.