A low detection limit penicillin biosensor based on single graphene nanosheets preadsorbed with hematein/ionic liquids/penicillinase

• DOI: 10.1016/j.msec.2014.02.012
• Publication Date: 2014-02-17T06:46:31Z
• Authors: Yueting Wu; Lele Tang; Linhong Huang; Zhizhong Han; Jian Wang; Haibo Pan
• Keywords: Hydrolysis; Ionic Liquids; Penicillanic Acid; Biosensing Techniques; Penicillins; Hydrogen-Ion Concentration; Penicillinase; 01 natural sciences; 0104 chemical sciences; Limit of Detection; Electrochemistry; Graphite; Hematoxylin; Electrodes

In this study, we reported on a low detection limit penicillin biosensor with layer-by-layer (LbL) film containing single-graphene nanosheets (SGNs) preadsorbed with hematein, ionic liquids (ILs) and penicillinase. The penicillinase catalyzes the hydrolysis of penicillin to penicilloic acid, where H(+) is liberated and monitored amperometrically with hematein as a pH indicator. The SGN-hematein/ILs/penicillinase biosensor exhibited excellent performance for penicillin in PBS with a wide range from 1.25×10(-13) to 7.5×10(-3)M, and a low detection limit of 10(-13)M (0.04ppt, S/N≥3). Furthermore, the detection of penicillin concentration in real sample (milk) had acceptable accuracy with the assay system.