Construction of a biocompatible system of hemoglobin based on AuNPs-carbon aerogel and ionic liquid for amperometric biosensor

Carbon aerogel (CA) composite has potential application in biosensor design. In this article, AuNPs-carbon aerogel (Au-CA) was prepared by ethylene glycol (EG) reducing method, and its morphology was characterized by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Furthermore, a novel biocompatible platform based on Au-CA and ionic liquid (IL) was applied to the immobilization of hemoglobin (Hb) for fabricating amperometric biosensor. Results of spectroscopic and electrochemical examinations indicated that the platform could provide more sites and channels for the immobilization of Hb, aiding in the prevention of the denaturation and leakage of Hb, and enhancing the electron conductivity. In addition, the electrocatalytic property of the biosensor was investigated using hydrogen peroxide (H2O2) and nitrite (NO2−) as model compounds. The corresponding results revealed the biosensor has fast responses (within 7 s), good dynamic response ranges and low detection limits (2.0 μM for H2O2 and 1.3 μM for NO2−).